Method for operating terminal and base station in wireless communication system, and device supporting same

ABSTRACT

Disclosed are: a method for operating a terminal and a base station in a wireless communication system; and a device supporting same. According to an embodiment applicable to the present disclosure, a terminal may: acquire resource information for setting a transmission mode, in which data generated from the same information is transmitted through a plurality of physical downlink shared channels (PDSCHs) by a base station, and on this basis, transmitting the data through the plurality of PDSCHs; and acquire related data information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/417,000, filed on Jun. 21, 2021, which is a National Stageapplication under 35 U.S.C. § 371 of International Application No.PCT/KR2019/018326, filed on Dec. 23, 2019, which claims the benefit ofKorean Application No. 10-2018-0167879, filed on Dec. 21, 2018. Thedisclosures of the prior applications are incorporated by reference intheir entirety.

TECHNICAL FIELD

The following relates to a wireless communication system, and moreparticularly, a method for operating a terminal and a base stationrelated to an operation of obtaining resource information through whichdata information is transmitted when the terminal obtains the datainformation based on the same information through a plurality ofphysical downlink shared channels (PDSCHs) in a wireless communicationsystem, and a device supporting the same.

BACKGROUND

Wireless access systems have been widely deployed to provide varioustypes of communication services such as voice or data. In general, awireless access system is a multiple access system that supportscommunication of multiple users by sharing available system resources (abandwidth, transmission power, etc.) among them. For example, multipleaccess systems include a Code Division Multiple Access (CDMA) system, aFrequency Division Multiple Access (FDMA) system, a Time DivisionMultiple Access (TDMA) system, an Orthogonal Frequency Division MultipleAccess (OFDMA) system, and a Single Carrier Frequency Division MultipleAccess (SC-FDMA) system.

As more communication devices have demanded higher communicationcapacity, enhanced mobile broadband (eMBB) communication technologyrelative to legacy radio access technology (RAT) has been introduced. Inaddition, a communication system considering services/UEs sensitive toreliability and latency as well as massive machine type communication(MTC) for providing various services anytime and anywhere by connectinga plurality of devices and objects to each other has been introduced.Thus, the new generation RAT considering eMBB communication, massiveMTC, ultra-reliable and low-latency communication (URLLC), etc. havebeen introduced.

SUMMARY

An object of the present disclosure is to provide a method for operatinga terminal and a base station in a wireless communication system, anddevices supporting the same.

The technical objects that can be achieved through the presentdisclosure are not limited to what has been particularly describedhereinabove and other technical objects not described herein will bemore clearly understood by persons skilled in the art from the followingdetailed description.

The present disclosure provides a method for operating a terminal and abase station in a wireless communication system, and devices therefor.

As an example of the present disclosure, a method for operating aterminal in a wireless communication system may include: receivingdownlink control information (DCI) including a plurality of transmissionconfiguration indicator (TCI) states from a base station; obtaining,from the base station, mode information related to a first mode fortransmission of a plurality of data, the plurality of data being basedon the same information; based on the DCI and the mode information,assuming that (i) data reception via a plurality of physical downlinkshared channels (PDSCHs) is scheduled by the DCI, and (ii) data receivedvia the plurality of PDSCHs is based on the same information; obtainingresource information about the plurality of PDSCHs based on theassumption; and obtaining data information via the plurality of PDSCHsbased on the resource information.

In the present disclosure, the DCI may include two TCI states, whereinthe plurality of PDSCHs may include two PDSCHs.

As a specific example, based on a size of precoding resource block group(PRG) bundling configured for the terminal: (i) the resource informationabout the plurality of PDSCHs may be determined based on a localized PRGconfiguration based on the size of the PRG bundling being configuredwith a wideband PRG; and (ii) the resource information about theplurality of PDSCHs may be determined based on an interleaved PRGconfiguration based on the size of the PRG bundling being set to 2 or 4.

As another specific example, the method may further include:independently determining a frequency position of a phase trackingreference signal (PT-RS) for each of the PDSCHs based on respectivefrequency resources for the two PDSCHs; and receiving the PT-RS for eachof the PDSCHs based on the frequency position of the PT-RS for each ofthe PDSCHs.

As another specific example, the DCI may include information for twotransport blocks (TB), wherein, based on information related to one ofthe two TBs related to the DCI, the resource information about the twoPDSCHs may be determined based on one of a spatial division multiplexing(SDM) mode, a time division multiplexing (TDM) mode, and a frequencydivision multiplexing (FDM) mode.

As another specific example, the resource information about the twoPDSCHs may include frequency resource information about each of the twoPDSCHs determined based on information related to one transport block(TB) in information for two TBs included in the DCI.

Herein, based on a configuration of precoding resource block group (PRG)bundling configured for the terminal, a PRG bundling mode of one of alocalized PRG or an interleaved PRG may be configured for the terminal,wherein the frequency resource information may be configured differentlybetween the two PDSCHs based on (i) the configured PRG mode and (ii) theinformation related to the one TB.

More specifically, based on an odd number of total resource block group(RBG) sizes allocated to the terminal: (i) based on a first modulationand coding scheme (MCS) for a first PDSCH among the PDSCHs being higherthan a second MCS for a second PDSCH among the PDSCHs, one more RBG maybe allocated for the first PDSCH; (ii) based on the first MCS beinghigher than the second MCS, one more RBG may be allocated for the secondPDSCH; or (iii) based on the first MCS being equal to the second MCS,one more RBG may be allocated for the first PDSCH or the second PDSCH;or (iv) one more RBG is allocated for one PBSCH determined based on theinformation related to the one TB among the PDSCHs.

In the present disclosure, the information related to the one TB may beinformation related to a TB corresponding to a second order between thetwo TBs, wherein the information related to the TB corresponding to thesecond order may include at least one of the followings:

-   -   a new data indicator (NDI) related to the second TB;    -   a redundancy version (RV) related to the second TB; or    -   a modulating and coding scheme (MCS) related to the second TB.

As another specific example, the resource information about the twoPDSCHs may include time resource information about each of the twoPDSCHs determined based on information related to one transport block(TB) in information for two TBs included in the DCI.

Herein, the time resource information may be related to an offsetbetween time resource positions for the two PDSCHs, wherein frequencyresources for the two PDSCHs may be identically configured.

As another specific example, the obtaining of the data information bythe terminal via the two PDSCHs may include: obtaining firstdemodulation reference signal (DMRS) port information for a first PDSCHbased on antenna port related information included in the DCI; obtainingsecond DMRS port information for a second PDSCH based on informationrelated to one of the two TBs related to the DCI; and receiving the datainformation via the first PDSCH and the second PDSCH based on the firstDMRS port information and the second DMRS port information.

In the present disclosure, the two PDSCHs may each be related to two TCIstates, wherein the two PDSCHs may be received from differenttransmission reception points.

As another example of the present disclosure, a terminal operating in awireless communication system may include: at least one transmitter; atleast one receiver; at least one processor; and at least one memoryoperably connected to the at least one processor and configured to storeinstructions for causing the at least one processor to perform aspecific operation when executed, wherein the specific operation mayinclude: receiving downlink control information (DCI) including aplurality of transmission configuration indicator (TCI) states from abase station; obtaining, from the base station, mode information relatedto a first mode for transmission of a plurality of data, the data beingbased on the same information; based on the DCI and the modeinformation, assuming that (i) data reception via a plurality ofphysical downlink shared channels (PDSCHs) is scheduled by the DCI, and(ii) data received via the plurality of PDSCHs is based on the sameinformation; obtaining resource information about the plurality ofPDSCHs based on the assumption; and obtaining data information via theplurality of PDSCHs based on the resource information.

In the present disclosure, the terminal may communicate with at leastone of a mobile terminal, a network, or an autonomous vehicle other thana vehicle containing the terminal.

As another example of the present disclosure, a base station operatingin a wireless communication system may include at least one transmitter;at least one receiver; at least one processor; and at least one memoryoperably connected to the at least one processor and configured to storeinstructions for causing the at least one processor to perform aspecific operation when executed, wherein the specific operation mayinclude: transmitting downlink control information (DCI) including aplurality of transmission configuration indicator (TCI) states to aterminal; providing the terminal with mode information related to afirst mode for transmission of a plurality of data, the plurality ofdata being based on the same information; and transmitting datainformation based on the same information on a resource indicated byresource information about a plurality of physical downlink sharedchannels (PDSCHs) via the plurality of PDSCHs based on the DCI and themode information.

The above-described aspects of the present disclosure are merely some ofthe preferred embodiments of the present disclosure, and variousembodiments reflecting the technical features of the present disclosuremay be derived and understood by those of ordinary skill in the artbased on the following detailed description of the disclosure.

As is apparent from the above description, the embodiments of thepresent disclosure have the following effects.

According to the present disclosure, a base station may schedule aplurality of PDSCHs (or codewords (CWs) or transport blocks (TBs)) for aterminal through one DCI, and the terminal may receive the plurality ofPDSCHs through one TRP or a plurality of TRPs.

To this end, the base station should provide the terminal with resourceinformation (e.g., frequency/time resource information, etc.) throughwhich the plurality of PDSCHs is transmitted. However, according to theconventional 5G NR system, it is difficult for the base station toprovide resource information for a plurality of PDSCHs to the terminalthrough one DCI.

On the other hand, according to the present disclosure, the base stationand the terminal may transmit and receive the resource information forthe plurality of PDSCHs through one DCI, and accordingly, the basestation may schedule the plurality of PDSCHs through the one DCI.

In addition, according to the present disclosure, the base station andthe terminal may transmit and receive resource information for aplurality of PDSCHs with low signaling overhead.

It will be appreciated by persons skilled in the art that that theeffects that can be achieved through the embodiments of the presentdisclosure are not limited to those described above and otheradvantageous effects of the present disclosure will be more clearlyunderstood from the following detailed description. That is, unintendedeffects according to implementation of the present disclosure may bederived by those skilled in the art from the embodiments of the presentdisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure, provide embodiments of the presentdisclosure together with detail explanation. Yet, a technicalcharacteristic of the present disclosure is not limited to a specificdrawing. Characteristics disclosed in each of the drawings are combinedwith each other to configure a new embodiment. Reference numerals ineach drawing correspond to structural elements.

FIG. 1 is a diagram illustrating physical channels and a general signaltransmission method using the physical channels.

FIG. 2 is a diagram illustrating a radio frame structure in an NR systemto which embodiments of the present disclosure are applicable.

FIG. 3 is a diagram illustrating a slot structure in an NR system towhich embodiments of the present disclosure are applicable.

FIG. 4 is a diagram illustrating a self-contained slot structure in anNR system to which embodiments of the present disclosure are applicable.

FIG. 5 is a diagram illustrating the structure of one REG in an NRsystem to which embodiments of the present disclosure are applicable.

FIGS. 6A and 6B are diagrams schematically illustrating an example of afront loaded DMRS of a first DMRS configuration type applicable to thepresent disclosure.

FIG. 7 is a diagram illustrating exemplary cases in which two physicaldownlink shared channels (PDSCHs) overlap with each other in time and/orfrequency resources, which are applicable to the present disclosure.

FIG. 8 is a simplified diagram illustrating a single physical downlinkcontrol channel (PDCCH) system operation applicable to the presentdisclosure.

FIG. 9 is a simplified diagram illustrating a configuration in which auser equipment (UE) receives PDSCHs through two transmission andreception points (TRPs)/beam(s).

FIG. 10 is a simplified diagram illustrating exemplary operations of aUE and a base station (BS) (e.g., an entity including TRP #1 and TRP #2)applicable to the present disclosure.

FIG. 11 is a simplified diagram illustrating operations of a UE and a BSaccording to an example of the present disclosure, FIG. 12 is aflowchart illustrating a UE operation according to an example of thepresent disclosure, and FIG. 13 is a flowchart illustrating a BSoperation according to an example of the present disclosure.

FIG. 14 is a diagram schematically illustrating an exemplary operationof a UE and a base station (e.g., an object including TRP #1 and TRP #2)applicable to the present disclosure.

FIG. 15 is a diagram schematically illustrating the operation of a UEand a base station according to an example of the present disclosure,FIG. 16 is a flowchart of an operation of the UE according to an exampleof the present disclosure, and FIG. 17 is a flowchart of an operation ofthe base station according to an example of the present disclosure.

FIGS. 18 to 22 are diagrams illustrating examples of PRGs for respectivecodewords according to the present disclosure.

FIGS. 23 to 25 are diagrams illustrating examples of PRGs for respectivecodewords based on an RV value according to the present disclosure.

FIG. 26 is a diagram illustrating an example of slot allocation for eachcodeword applicable to the present disclosure.

FIG. 27 is a diagram illustrating a time domain pattern of a PT-RSapplicable to the present disclosure.

FIG. 28 is a diagram illustrating another example of a PRG for eachcodeword according to the present disclosure.

FIG. 29 is a diagram illustrating an example of a PRG configuration foreach TRP according to the present disclosure.

FIG. 30 is a diagram schematically illustrating an exemplary operationof a UE and a base station (e.g., an object including TRP #1 and TRP #2)applicable to the present disclosure.

FIG. 31 is a diagram schematically illustrating the operation of a UEand a base station according to an example of the present disclosure,FIG. 32 is a flowchart of an operation of the UE according to an exampleof the present disclosure, and FIG. 33 is a flowchart of an operation ofthe base station according to an example of the present disclosure.

FIG. 34 is a diagram illustrating an exemplary communication systemapplied to the present disclosure.

FIG. 35 is a block diagram illustrating an example of wireless devicesapplied to the present disclosure.

FIG. 36 is a block diagram illustrating another example of wirelessdevices applied to the present disclosure.

FIG. 37 is a block diagram illustrating a portable device applied to thepresent disclosure.

FIG. 38 is a block diagram illustrating a vehicle or autonomous drivingvehicle applied to the present disclosure.

DETAILED DESCRIPTION

The embodiments of the present disclosure described below arecombinations of elements and features of the present disclosure inspecific forms. The elements or features may be considered selectiveunless otherwise mentioned. Each element or feature may be practicedwithout being combined with other elements or features. Further, anembodiment of the present disclosure may be constructed by combiningparts of the elements and/or features. Operation orders described inembodiments of the present disclosure may be rearranged. Someconstructions or elements of any one embodiment may be included inanother embodiment and may be replaced with corresponding constructionsor features of another embodiment.

In the description of the attached drawings, a detailed description ofknown procedures or steps of the present disclosure will be avoidedleast it should obscure the subject matter of the present disclosure. Inaddition, procedures or steps that could be understood to those skilledin the art will not be described either.

Throughout the specification, when a certain portion “includes” or“comprises” a certain component, this indicates that other componentsare not excluded and may be further included unless otherwise noted. Theterms “unit”, “-or/er” and “module” described in the specificationindicate a unit for processing at least one function or operation, whichmay be implemented by hardware, software or a combination thereof. Inaddition, the terms “a or an”, “one”, “the” etc. may include a singularrepresentation and a plural representation in the context of the presentdisclosure (more particularly, in the context of the following claims)unless indicated otherwise in the specification or unless contextclearly indicates otherwise.

In the embodiments of the present disclosure, a description is mainlymade of a data transmission and reception relationship between a BaseStation (BS) and a User Equipment (UE). A BS refers to a UE node of anetwork, which directly communicates with a UE. A specific operationdescribed as being performed by the BS may be performed by an upper nodeof the BS.

Namely, it is apparent that, in a network comprised of a plurality ofnetwork nodes including a BS, various operations performed forcommunication with a UE may be performed by the BS, or network nodesother than the BS. The term ‘BS’ may be replaced with a fixed station, aNode B, an evolved Node B (eNode B or eNB), gNode B (gNB), an AdvancedBase Station (ABS), an access point, etc.

In the embodiments of the present disclosure, the term UE may bereplaced with a UE, a Mobile Station (MS), a Subscriber Station (SS), aMobile Subscriber Station (MSS), a mobile UE, an Advanced Mobile Station(AMS), etc.

A transmission end is a fixed and/or mobile node that provides a dataservice or a voice service and a reception end is a fixed and/or mobilenode that receives a data service or a voice service. Therefore, a UEmay serve as a transmission end and a BS may serve as a reception end,on an UpLink (UL). Likewise, the UE may serve as a reception end and theBS may serve as a transmission end, on a DownLink (DL).

The embodiments of the present disclosure may be supported by standardspecifications disclosed for at least one of wireless access systemsincluding an Institute of Electrical and Electronics Engineers (IEEE)802.xx system, a 3rd Generation Partnership Project (3GPP) system, a3GPP Long Term Evolution (LTE) system, 3GPP 5G NR system and a 3GPP2system. In particular, the embodiments of the present disclosure may besupported by the standard specifications, 3GPP TS 38.211, 3GPP TS38.212, 3GPP TS 38.213, 3GPP TS 38.321 and 3GPP TS 38.331. That is, thesteps or parts, which are not described to clearly reveal the technicalidea of the present disclosure, in the embodiments of the presentdisclosure may be explained by the above standard specifications. Allterms used in the embodiments of the present disclosure may be explainedby the standard specifications.

Reference will now be made in detail to the embodiments of the presentdisclosure with reference to the accompanying drawings. The detaileddescription, which will be given below with reference to theaccompanying drawings, is intended to explain exemplary embodiments ofthe present disclosure, rather than to show the only embodiments thatcan be implemented according to the disclosure.

The following detailed description includes specific terms in order toprovide a thorough understanding of the present disclosure. However, itwill be apparent to those skilled in the art that the specific terms maybe replaced with other terms without departing the technical spirit andscope of the present disclosure.

Hereinafter, 3GPP NR system is explained, which are examples of wirelessaccess systems.

Technology described below may be applied to various wireless accesssystems such as code division multiple access (CDMA), frequency divisionmultiple access (FDMA), time division multiple access (TDMA), orthogonalfrequency division multiple access (OFDMA), and single carrier frequencydivision multiple access (SC-FDMA).

To clarify technical features of the present disclosure, embodiments ofthe present disclosure are described focusing upon a 3GPP NR system.However, the embodiments proposed in the present disclosure may beequally applied to other wireless systems (e.g., 3GPP LTE, IEEE 802.16,and IEEE 802.11).

1. NR System

1.1. Physical Channels and General Signal Transmission

In a wireless access system, a UE receives information from a basestation on a DL and transmits information to the base station on a UL.The information transmitted and received between the UE and the basestation includes general data information and various types of controlinformation. There are many physical channels according to thetypes/usages of information transmitted and received between the basestation and the UE.

FIG. 1 illustrates physical channels and a general signal transmissionmethod using the physical channels, which may be used in embodiments ofthe present disclosure.

A UE performs initial cell search such as synchronization establishmentwith a BS in step S11 when the UE is powered on or enters a new cell. Tothis end, the UE may receive a primary synchronization channel (P-SCH)and a secondary synchronization channel (S-SCH) from the BS, establishsynchronization with the BS, and acquire information such as a cellidentity (ID).

Thereafter, the UE may receive a physical broadcast channel (PBCH) fromthe BS to acquire broadcast information in the cell.

Meanwhile, the UE may receive a DL reference signal (RS) in the initialcell search step to confirm a DL channel state.

Upon completion of initial cell search, the UE may receive a physicaldownlink control channel (PDCCH) and a physical downlink shared channel(PDSCH) according to information included in the PDCCH to acquire moredetailed system information in step S12.

Next, the UE may perform a random access procedure such as steps S13 toS16 to complete access to the BS. To this end, the UE may transmit apreamble through a physical random access channel (PRACH) (S13) andreceive a random access response (RAR) to the preamble through the PDCCHand the PDSCH corresponding to the PDCCH (S14). The UE may transmit aphysical uplink shared channel (PUSCH). In the case of contention-basedrandom access, a contention resolution procedure including transmissionof a PRACH signal (S15) and reception of a PDCCH signal and a PDSCHsignal corresponding to the PDCCH signal (S16) may be additionallyperformed.

The UE which has performed the above procedures may receive a PDCCHsignal and/or a PDSCH signal (S17) and transmit a PUSCH signal and/or aphysical uplink control channel (PUCCH) signal (S18) as a general UL/DLsignal transmission procedure.

Control information that the UE transmits to the BS is referred to asuplink control information (UCI). The UCI includes a hybrid automaticrepeat and request (HARD) acknowledgement (ACK)/negative ACK (NACK)signal, a scheduling request (SR), a channel quality indicator (CQI), aprecoding matrix index (PMI), a rank indicator (RI), or beam indication(BI) information.

In an NR system, the UCI is generally periodically transmitted on thePUCCH. However, according to an embodiment (if control information andtraffic data should be transmitted simultaneously), the controlinformation and traffic data may be transmitted on the PUSCH. Inaddition, the UCI may be transmitted aperiodically on the PUSCH, uponreceipt of a request/command from a network.

1.2. Radio Frame Structure

FIG. 2 is a diagram illustrating a radio frame structure in an NR systemto which embodiments of the present disclosure are applicable.

In the NR system, UL and DL transmissions are based on a frame asillustrated in FIG. 2. One radio frame is 10 ms in duration, defined bytwo 5-ms half-frames. One half-frame is defined by five 1-ms subframes.One subframe is divided into one or more slots, and the number of slotsin a subframe depends on an SCS. Each slot includes 12 or 14 OFDM(A)symbols according to a CP. Each slot includes 14 symbols in a normal CPcase, and 12 symbols in an extended CP case. Herein, a symbol mayinclude an OFDM symbol (or a CP-OFDM) symbol and an SC-FDMA symbol (or aDFT-s-OFDM symbol).

Table 1 lists the number of symbols per slot, the number of slots perframe, and the number of slots per subframe in the normal CP case, andTable 2 lists the number of symbols per slot, the number of slots perframe, and the number of slots per subframe in the extended CP case.

TABLE 1 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16 5 14 320 32

TABLE 2 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)2 12 40 4

In the above tables, N^(slot) _(symb) denotes the number of symbols in aslot, N^(frame,μ) _(slot) denotes the number of slots in a frame, andN^(subframe,μ) _(slot) denotes the number of slots in a subframe.

In the NR system to which the present disclosure is applicable,different OFDM(A) numerologies (e.g., SCSs, CP length, and so on) may beconfigured for a plurality of cells aggregated for a UE. Therefore, the(absolute) duration of a time resource (e.g., an SF, slot, or TTI) (forthe convenience of description, generically referred to as a time unit(TU)) including the same number of symbols may be different between theaggregated cells.

NR supports multiple numerologies (e.g., subcarrier spacings (SCSs)) tosupport various 5th generation (5G) services. For example, the NR systemsupports a wide area in conventional cellular bands for an SCS of 15kHz, a dense urban environment, low latency, and a wide carrierbandwidth for an SCS of 30/60 kHz, and a bandwidth wider than 24.25 GHzto overcome phase noise, for an SCS of 60 kHz or above.

An NR frequency band is defined by two types of frequency ranges, FR1and FR2. FR1 and FR2 may be configured as described in Table 3 below.FR2 may represent millimeter wave (mmW).

TABLE 3 Frequency range designation Corresponding frequency range FR1 410 MHz-7125 MHz FR2 24250 MHz-52600 MHz

FIG. 3 is a diagram illustrating a slot structure in an NR system towhich embodiments of the present disclosure are applicable.

One slot includes a plurality of symbols in the time domain. Forexample, one slot includes 7 symbols in a normal CP case and 6 symbolsin an extended CP case.

A carrier includes a plurality of subcarriers in the frequency domain.An RB is defined by a plurality of (e.g., 12) consecutive subcarriers inthe frequency domain.

A bandwidth part (BWP), which is defined by a plurality of consecutive(P)RBs in the frequency domain, may correspond to one numerology (e.g.,SCS, CP length, and so on).

A carrier may include up to N (e.g., 5) BWPs. Data communication may beconducted in an activated BWP, and only one BWP may be activated for oneUE. In a resource grid, each element is referred to as an RE, to whichone complex symbol may be mapped.

FIG. 4 is a diagram illustrating a self-contained slot structures in anNR system to which embodiments of the present disclosure are applicable.

In FIG. 4, the hatched area (e.g., symbol index=0) indicates a DLcontrol region, and the black area (e.g., symbol index=13) indicates aUL control region. The remaining area (e.g., symbol index=1 to 12) maybe used for DL or UL data transmission.

Based on this structure, a base station and a UE may sequentiallyperform DL transmission and UL transmission in one slot. That is, thebase station and UE may transmit and receive not only DL data but also aUL ACK/NACK for the DL data in one slot. Consequently, this structuremay reduce a time required until data retransmission when a datatransmission error occurs, thereby minimizing the latency of a finaldata transmission.

In this self-contained slot structure, a predetermined length of timegap is required to allow the base station and UE to switch fromtransmission mode to reception mode and vice versa. To this end, in theself-contained slot structure, some OFDM symbols at the time ofswitching from DL to UL may be configured as a guard period (GP).

Although it has been described above that the self-contained slotstructure includes both DL and UL control regions, these control regionsmay be selectively included in the self-contained slot structure. Inother words, the self-contained slot structure according to the presentdisclosure may include either the DL control region or the UL controlregion as well as both the DL and UL control regions as illustrated inFIG. 5.

Further, the order of the regions in one slot may vary according toembodiments. For example, one slot may be configured in the order of DLcontrol region, DL data region, UL control region, and UL data region,or UL control region, UL data region, DL control region, and DL dataregion.

A PDCCH may be transmitted in the DL control region, and a PDSCH may betransmitted in the DL data region. A PUCCH may be transmitted in the ULcontrol region, and a PUSCH may be transmitted in the UL data region.

The PDCCH may deliver downlink control information (DCI), for example,DL data scheduling information, UL data scheduling information, and soon. The PUCCH may deliver uplink control information (UCI), for example,an ACK/NACK for DL data, channel state information (CSI), a schedulingrequest (SR), and so on.

The PDSCH conveys DL data (e.g., DL-shared channel transport block(DL-SCH TB)) and uses a modulation scheme such as quadrature phase shiftkeying (QPSK), 16-ary quadrature amplitude modulation (16QAM), 64QAM, or256QAM. A TB is encoded into a codeword. The PDSCH may deliver up to twocodewords. Scrambling and modulation mapping are performed on a codewordbasis, and modulation symbols generated from each codeword are mapped toone or more layers (layer mapping). Each layer together with ademodulation reference signal (DMRS) is mapped to resources, generatedas an OFDM symbol signal, and transmitted through a correspondingantenna port.

The PDCCH carries DCI and uses QPSK as a modulation scheme. One PDCCHincludes 1, 2, 4, 8, or 16 control channel elements (CCEs) according toan aggregation level (AL). One CCE includes 6 resource element groups(REGs). One REG is defined by one OFDM symbol by one (P)RB.

FIG. 5 is a diagram illustrating the structure of one REG in an NRsystem to which embodiments of the present disclosure are applicable.

In FIG. 5, D represents an RE to which DCI is mapped, and R representsan RE to which a DMRS is mapped. The DMRS is mapped to REs #1, #5, and#9 along the frequency axis in one symbol.

The PDCCH is transmitted in a control resource set (CORESET). A CORESETis defined as a set of REGs having a given numerology (e.g., SCS, CPlength, and so on). A plurality of CORESETs for one UE may overlap witheach other in the time/frequency domain. A CORESET may be configured bysystem information (e.g., a master information block (MIB)) or byUE-specific higher layer (RRC) signaling. Specifically, the number ofRBs and the number of symbols (up to 3 symbols) included in a CORESETmay be configured by higher-layer signaling.

The PUSCH delivers UL data (e.g., UL-shared channel transport block(UL-SCH TB)) and/or UCI based on a CP-OFDM waveform or a DFT-s-OFDMwaveform. When the PUSCH is transmitted in the DFT-s-OFDM waveform, theUE transmits the PUSCH by transform precoding. For example, whentransform precoding is impossible (e.g., disabled), the UE may transmitthe PUSCH in the CP-OFDM waveform, while when transform precoding ispossible (e.g., enabled), the UE may transmit the PUSC in the CP-OFDM orDFT-s-OFDM waveform. A PUSCH transmission may be dynamically scheduledby a UL grant in DCI, or semi-statically scheduled by higher-layer(e.g., RRC) signaling (and/or layer 1 (L1) signaling such as a PDCCH)(configured grant). The PUSCH transmission may be performed in acodebook-based or non-codebook-based manner.

The PUCCH delivers UCI, an HARQ-ACK, and/or an SR and is classified as ashort PUCCH or a long PUCCH according to the transmission duration ofthe PUCCH. Table 3 lists exemplary PUCCH formats.

TABLE 4 PUCCH Length in OFDM Number format symbols N_(symb) ^(PUCCH) ofbits Usage Etc 0 1-2  ≤2 HARQ, SR Sequence selection 1 4-14 ≤2 HARQ,[SR] Sequence modulation 2 1-2  >2 HARQ, CSI, [SR] CP-OFDM 3 4-14 >2HARQ, CSI, [SR] DFT-s-OFDM (no UE multiplexing) 4 4-14 >2 HARQ, CSI,[SR] DFT-s-OFDM (Pre DFT OCC)

PUCCH format 0 conveys UCI of up to 2 bits and is mapped in asequence-based manner, for transmission. Specifically, the UE transmitsspecific UCI to the base station by transmitting one of a plurality ofsequences on a PUCCH of PUCCH format 0. Only when the UE transmits apositive SR, the UE transmits the PUCCH of PUCCH format 0 in a PUCCHresource for a corresponding SR configuration.

PUCCH format 1 conveys UCI of up to 2 bits and modulation symbols of theUCI are spread with an OCC (which is configured differently whetherfrequency hopping is performed) in the time domain. The DMRS istransmitted in a symbol in which a modulation symbol is not transmitted(i.e., transmitted in time division multiplexing (TDM)).

PUCCH format 2 conveys UCI of more than 2 bits and modulation symbols ofthe DCI are transmitted in frequency division multiplexing (FDM) withthe DMRS. The DMRS is located in symbols #1, #4, #7, and #10 of a givenRB with a density of ⅓. A pseudo noise (PN) sequence is used for a DMRSsequence. For 1-symbol PUCCH format 2, frequency hopping may beactivated.

PUCCH format 3 does not support UE multiplexing in the same PRBS, andconveys UCI of more than 2 bits. In other words, PUCCH resources ofPUCCH format 3 do not include an OCC. Modulation symbols are transmittedin TDM with the DMRS.

PUCCH format 4 supports multiplexing of up to 4 UEs in the same PRBS,and conveys UCI of more than 2 bits. In other words, PUCCH resources ofPUCCH format 3 includes an OCC. Modulation symbols are transmitted inTDM with the DMRS.

1.3. DCI Format

In the NR system to which the present disclosure is applicable, thefollowing DCI formats may be supported. First, the NR system may supportDCI format 0_0 and DCI format 0_1 as a DCI format for PUSCH schedulingand support DCI format 1_0 and DCI format 1_1 as a DCI format for PDSCHscheduling. In addition, as DCI formats usable for other purposes, theNR system may additionally support DCI format 2_0, DCI format 2_1, DCIformat 2_2, and DCI format 2_3.

Herein, DCI format 0_0 is used to schedule a transmission block(TB)-based (or TB-level) PUSCH. DCI format 0_1 may be used to schedule aTB-based (or TB-level) PUSCH or code block group (CBG)-based (orCBG-level) PUSCH (in the case in which CBG-based signal transmission andreception is configured).

In addition, DCI format 1_0 may be used to schedule TB-based (orTB-level) PDSCH. DCI format 1_1 may be used to schedule TB-based (orTB-level) PDSCH or CBG-based (or CBG-level) PDSCH (in the case in whichCBG-based signal transmission and reception is configured).

In addition, DCI format 2_0 may be used to notify UEs of a slot format.DCI format 2_1 may be used to notify UEs of PRB(s) and OFDM symbol(s) inwhich a specific UE assumes that no transmission is intended therefor.DCI format 2_2 may be used to transmit transmission power control (TPC)commands for a PUCCH and a PUSCH. DCI format 2_3 may be used to transmita group of TPC commands for SRS transmission by one or more UEs.

More specifically, DCI format 1_1 includes an MCS/new data indicator(NDI)/redundancy version (RV) field for transport block (TB) 1. Onlywhen a higher-layer parameter maxNrofCodeWordsScheduledByDCI in ahigher-layer parameter PDSCH-Config is set to n2 (i.e., 2), DCI format1_1 may further include an MCS/NDI/RV field for TB 2.

Particularly, when the higher-layer parametermaxNrofCodeWordsScheduledByDCI is set to n2 (i.e., 2), it may bedetermined based on a combination of the MCS field and the RV fieldwhether a TB is actually enabled or disabled. More specifically, whenthe MCS field is set to 26 and the RV field is set to 1 for a specificTB, the TB may be disabled.

Detailed features of the DCI formats may be supported by 3GPP TS 38.212.That is, obvious steps or parts which are not explained by DCIformat-related features may be explained with reference to the abovedocument. In addition, all terms disclosed in the present document maybe explained by the above standard document.

1.4. Control Resource Set (CORESET)

One CORESET includes N^(CORESET) _(RB) RBs in the frequency domain andN^(CORESET) _(symb) symbols (having a value of 1, 2, or 3) in the timedomain.

One control channel element (CCE) includes 6 resource element groups(REGs) and one REG is equal to one RB in one OFDM symbol. REGs in theCORESET are numbered in a time-first manner. Specifically, the REGs arenumbered starting with ‘0’ for the first OFDM symbol and thelowest-numbered RB in the CORESET.

A plurality of CORESETs may be configured for one UE. Each CORESET isrelated only to one CCE-to-REG mapping.

CCE-to-REG mapping for one CORESET may be interleaved ornon-interleaved.

Configuration information for the CORESET may be configured by a higherlayer parameter ControlResourceSet IE.

In addition, configuration information for CORESET 0 (e.g., commonCORESET) may be configured by a higher layer parameterControlResourceSetZero IE.

1.5. Antenna Port Quasi Co-Location

One UE may be configured with a list of up to M transmissionconfiguration indicator (TCI) state configurations. The M TCI-stateconfigurations may be configured by a higher layer parameterPDSCH-Config to decode a PDSCH (by the UE) according to a detected PDCCHwith DCI intended for the UE and the given serving cell. Herein, M maybe determined depending on the capability of the UE.

Each TCI state contains parameters for configuring a quasi co-location(QCL) relationship between one or two DL reference signals and the DMRSports of the PDSCH. The QCL relationship is configured by the higherlayer parameter qcl-Type1 for a first DL RS and a higher layer parameterqcl-Type2 for a second DL RS (if configured). For the case of two DLRSs, the QCL types should not be the same, regardless of whether the RSsare the same DL RS or different DL RSs. The QCL type corresponding toeach DL RS is given by a higher layer parameter qcl-Type within a higherlayer parameter QCL Info and may have one of the following values.

-   -   ‘QCL-TypeA’: {Doppler shift, Doppler spread, average delay,        delay spread}    -   ‘QCL-TypeB’: {Doppler shift, Doppler spread}    -   ‘QCL-TypeC’: {Doppler shift, average delay}    -   ‘QCL-TypeD’: {Spatial Rx parameter}

The UE receives an activation command used to map up to 8 TCI states tocodepoints of a TCI field in the DCI. When a HARQ-ACK signalcorresponding to the PDSCH carrying the activation command istransmitted in slot #n, mapping between the TCI states and codepoints ofthe TCI field in the DCI may be applied starting from slot#(n+3*N^(subframe,μ) _(slot)+1). In this case, N^(subframe,μ) _(slot) isdetermined based on Table 1 or Table 2 described above. After the UEreceives initial higher layer configuration of TCI states and before theUE receives the activation command, the UE assumes that DM-RS port(s) ofa PDSCH of a serving cell are quasi co-located with an SS/PBCH blockdetermined in the initial access procedure with respect to ‘QCL-TypeA’.Additionally, the UE may assume that the DM-RS port(s) of the PDSCH ofthe serving cell are quasi co-located with the SS/PBCH block determinedin the initial access procedure also with respect to ‘QCL-TypeD’ at theabove timing.

If a higher layer parameter tci-PresentInDCI is set as ‘enabled’ for aCORESET scheduling the PDSCH, the UE assumes that the TCI field ispresent in a PDCCH of DCI format 1_1 transmitted on the CORESET. If thehigher layer parameter tci-PresentInDCI is not configured for theCORESET scheduling the PDSCH or the PDSCH is scheduled by DCI format 1_0and if a time offset between the reception of the DL DCI and thereception of the corresponding PDSCH is equal to or greater than athreshold Threshold-Sched-Offset (where the threshold is based on UEcapability), for determining PDSCH antenna port QCL, the UE assumes thata TCI state or QCL assumption for the PDSCH is identical to a TCI stateor QCL assumption applied to a CORESET used for PDCCH transmission.

If the higher layer parameter tci-PresentInDCI is set as ‘enabled’, theTCI field in the DCI scheduling a component carrier (CC) points toactivated TCI states in the scheduled CC or a DL BW, and the PDSCH isscheduled by DCI format 1_1, the UE uses a TCI-state according to theTCI field in the DCI in a detected PDCCH to determine PDSCH antenna portQCL. The UE may assume that DMRS ports of the PDSCH of a serving cellare quasi co-located with RS(s) in the TCI state with respect to QCLtype parameter(s) given by an indicated TCI state if the time offsetbetween the reception of the DL DCI and the reception of thecorresponding PDSCH is equal to or greater than the thresholdThreshold-Sched-Offset (where the threshold is determined based onreported UE capability). When the UE is configured with a single slotPDSCH, the indicated TCI state should be based on the activated TCIstates in a slot with the scheduled PDSCH. When the UE is configuredwith CORESET associated with a search space set for cross-carrierscheduling, the UE expects that the higher layer parametertci-PresentInDCI is set as ‘enabled’ for the CORESET. If one or more ofthe TCI states configured for the serving cell scheduled by the searchspace set contains ‘QCL-TypeD’, the UE expects the time offset betweenthe reception of the detected PDCCH in the search space set and thereception of the corresponding PDSCH is greater than or equal to thethreshold Threshold-Sched-Offset.

For both the cases when higher layer parameter tci-PresentInDCI is setto ‘enabled’ and the higher layer parameter tci-PresentInDCI is notconfigured in RRC connected mode, if the offset between the reception ofthe DL DCI and the reception of the corresponding PDSCH is less than thethreshold Threshold-Sched-Offset, the UE makes the followingassumptions. (i) DM-RS ports of a PDSCH of a serving cell are quasico-located with the RS(s) in a TCI state with respect to QCLparameter(s). (ii) In this case, the QCL parameter(s) are used for PDCCHQCL indication of the CORESET associated with a monitored search spacewith the lowest CORESET-ID in the latest slot in which one or moreCORESETs within an active BWP of the serving cell are monitored by theUE.

In this case, if the ‘QCL-TypeD’ of a PDSCH DM-RS is different from‘QCL-TypeD’ of a PDCCH DM-RS with which overlapping occurs in at leastone symbol, the UE is expected to prioritize the reception of the ePDCCHassociated with the corresponding CORESET. This operation may also beapplied to an intra-band CA case (when the PDSCH and the CORESET are indifferent CCs). If none of configured TCI states contains ‘QCL-TypeD’,the UE obtains the other QCL assumptions from the indicated TCI statesfor a scheduled PDSCH irrespective of the time offset between thereception of the DL DCI and the reception of the corresponding PDSCH.

For a periodic CSI-RS resource in an NZP-CSI-RS-ResourceSet configuredwith a higher layer parameter trs-Info, the UE should assume that that aTCI state indicates one of the following QCL type(s):

-   -   ‘QCL-TypeC’ with an SS/PBCH block and, when (QCL-TypeD) is        applicable, ‘QCL-TypeD’ with the same SS/PBCH block, or    -   ‘QCL-TypeC’ with an SS/PBCH block and, when (QCL-TypeD) is        applicable, ‘QCL-TypeD’ with a periodic CSI-RS resource in a        higher layer parameter NZP-CSI-RS-ResourceSet configured with        higher layer parameter repetition,

For a CSI-RS resource in the higher layer parameterNZP-CSI-RS-ResourceSet configured with the higher layer parametertrs-Info and without the higher layer parameter repetition, the UEshould assume that a TCI state indicates one of the following QCLtype(s):

-   -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with higher layer parameter        trs-Info and, when (QCL-TypeD) is applicable, ‘QCL-TypeD’ with        the same CSI-RS resource, or    -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with higher layer parameter        trs-Info and, when (QCL-TypeD) is applicable, ‘QCL-TypeD’ with        an SS/PBCH, or    -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info and, when (QCL-TyepD is) applicable,        ‘QCL-TypeD’ with a periodic CSI-RS resource in the higher layer        parameter NZP-CSI-RS-ResourceSet configured with the higher        layer parameter repetition, or    -   ‘QCL-TypeB’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info when ‘QCL-TypeD’ is not applicable.

For a CSI-RS resource in the higher layer parameterNZP-CSI-RS-ResourceSet configured with the higher layer parameterrepetition, the UE should assume that a TCI state indicates one of thefollowing QCL type(s):

-   -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info and, when (′QCL-TypeD) is applicable,        ‘QCL-TypeD’ with the same CSI-RS resource, or    -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info and, when (‘QCL-TypeD’ is) applicable,        ‘QCL-TypeD’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with higher layer parameter        repetition, or    -   ‘QCL-TypeC’ with an SS/PBCH block and, when (QCL-TypeD) is        applicable, ‘QCL-TypeD’ with the same SS/PBCH block.

For the DM-RS of PDCCH, the UE should assume that a TCI state indicatesone of the following QCL type(s):

-   -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info and, when (QCL-TypeD) is applicable,        ‘QCL-TypeD’ with the same CSI-RS resource, or    -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with higher layer parameter        trs-Info and, when (QCL-TypeD) is applicable, ‘QCL-TypeD’ with a        CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter repetition, or    -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured without higher layer parameter        trs-Info and without the higher layer parameter repetition and,        when (QCL-TypeD) is applicable, ‘QCL-TypeD’ with the same CSI-RS        resource.

For the DM-RS of the PDSCH, the UE should assume that a TCI stateindicates one of the following QCL type(s):

-   -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info and, when (QCL-TypeD) is applicable,        ‘QCL-TypeD’ with the same CSI-RS resource, or    -   ‘QCL-TypeA’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter trs-Info and, when (QCL-TypeD) is applicable,        ‘QCL-TypeD’ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured with the higher layer        parameter repetition, or    -   QCL-TypeA′ with a CSI-RS resource in the higher layer parameter        NZP-CSI-RS-ResourceSet configured without the higher layer        parameter trs-Info and without the higher layer parameter        repetition and, when (QCL-TypeD) is applicable, ‘QCL-TypeD’ with        the same CSI-RS resource.

In the present disclosure, QCL signaling may include all signalingconfigurations listed in the following table.

TABLE 5 QCL linkage for FR2 after RRC signalling SSB → TRS w.r.t averagedelay, Doppler shift, spatial RX parameters QCL type: C + D TRS → CSI-RSfor BM w.r.t. average delay, Doppler shift, delay spread. QCL type: A +D Doppler spread estimation TRS → CSI-RS for CSI w.r.t. average delay,Doppler shift, delay spread, QCL type: A Doppler spread estimation TRS →DMRS for PDCCH w.r.t. average delay, Doppler shift, delay QCL type: A +D spread, Doppler spread estimation TRS → DMRS for PDSCH w.r.t. averagedelay, Doppler shift, delay QCL type: A + D spread, Doppler spreadestimation SSB → CSI-RS for BM w.r.t. average delay, Doppler shift,spatial RX QCL type: C + D parameters SSB → CSI-RS for CSI w.r.t,spatial RX parameters QCL type: D SSB → DMRS for PDCCH (before TRS isconfigured) w.r.t. average delay, QCL type: A + D Doppler shift, delayspread, Doppler spread, spatial RX parameters SSB → DMRS for PDSCH(before TRS is configured) w.r.t. average delay, QCL type: A + D Dopplershift, delay spread, Doppler spread, spatial RX parameters CSI-RS for BM→ DMRS for PDCCH w.r.t. spatial RX parameters QCL type: D CSI-RS for BM→ DMRS for PDSCH w.r.t. spatial RX parameters QCL type: D CSI-RS for CSI→ DMRS for PDSCH w.r.t. average delay, Doppler shift, QCL type: A + Ddelay spread, Doppler spread, spatial RX parameters; Note: QCLparameters may not be derived directly from CSI-RS for CSI CSI-RS for BM→ CSI-RS for TRS/BM/CSI w.r.t. spatial RX parameters QCL type: D

In the following tables, if one row in the tables below has the same RStype, it is assumed that the same RS ID may be applied for the row.

In the present disclosure, when a CSI-RS resource is included in thehigher layer parameter NZP-CSI-RS-ResourceSet in which the higher layerparameter trs-Info is configured, the UE expects the following twopossible configurations for a higher layer parameter TCI-state.

TABLE 6 Valid TCI state DL RS 2 qcl-Type2 Configuration DL RS 1qcl-Type1 (if configured) (if configured) 1* SS/PBCH Block QCL-TypeCSS/PBCH Block QCL-TypeD 2* SS/PBCH Block QCL-TypeC CSI-RS (BM) QCL-TypeD

In Table 6, * represents a case in which QCL type-D is applicable. WhenQCL type-D is applicable, DL RS 2 and QCL type-2 need to be configuredfor the UE.

In the present disclosure, when a CSI-RS resource is included in thehigher layer parameter NZP-CSI-RS-ResourceSet in which the higher layerparameter trs-Info and the higher layer parameter repetition are notconfigured, the UE expects the following three possible configurationsfor the higher layer parameter TCI-state.

TABLE 7 Valid TCI state DL RS 2 qcl-Type2 Configuration DL RS 1qcl-Type1 (if configured) (if configured) 1 TRS QCL-TypeA TRS QCL-TypeD2** TRS QCL-TypeA SS/PBCH Block QCL-TypeD 3** TRS QCL-TypeA CSI-RS (BM)QCL-TypeD 4* TRS QCL-TypeB

In Table 7, * represents a case in which QCL type-D is not applicable.

In Table 7, ** represents a case in which QCL type-D is applicable. WhenQCL type-D is applicable, DL RS 2 and QCL type-2 need to be configuredfor the UE.

In the present disclosure, when a CSI-RS resource is included in thehigher layer parameter NZP-CSI-RS-ResourceSet in which the higher layerparameter repetition is configured, the UE expects the following threepossible configurations for the higher layer parameter TCI-state.

TABLE 8 Valid TCI state DL RS 2 qcl-Type2 Configuration DL RS 1qcl-Type1 (if configured) (if configured) 1 TRS QCL-TypeA TRS QCL-TypeD2 TRS QCL-TypeA CSI-RS (BM) QCL-TypeD 3 SS/PBCH Block QCL-TypeC SS/PBCHBlock QCL-TypeD

In Tables 9 and 10 below, if QCL type-D is applicable, DL RS 2 and QLCtype-2 need to be configured for the UE except a default case (e.g., thefourth row in Tables 9 and 10). When a TRS for DL is used for QCLtype-D, the TRS is a source RS for QCL type-D and thus needs to have anSS/PBCH block or CSI-RS.

For a PDCCH DMRS, the UE expects the following three possibleconfigurations for the higher layer parameter TCI-state. The fourthconfiguration is a default configuration and valid before the TRS isconfigured.

TABLE 9 Valid TCI state DL RS 2 qcl-Type2 Configuration DL RS 1qcl-Type1 (if configured) (if configured) 1 TRS QCL-TypeA TRS QCL-TypeD2 TRS QCL-TypeA CSI-RS (BM) QCL-TypeD 3** CSI-RS (CSl) QCL-TypeA CSI-RS(CSI) QCL-TypeD 4* SS/PBCH Block* QCL-TypeA SS/PBCH Block* QCL-TypeD

In Table 9, * represents a configuration that can be applied before theTRS is configured. In this case, the configuration may be a valid QCLassumption rather than a TCI state.

In Table 9, ** represents that QCL parameters may not be directlyderived from CSI-RS(s) (CSI).

For the PDCCH DMRS, the UE may expect only the following three availableconfigurations of the higher-layer parameter TCI-State, while the fourthconfiguration (in the fourth row in the following two tables) is validby default, before a TRS is configured.

TABLE 10 Valid TCI state DL RS 2 qcl-Type2 Configuration DL RS 1qcl-Type1 (if configured) (if configured) 1 TRS QCL-TypeA TRS QCL-TypeD2 TRS QCL-TypeA CSI-RS (BM) QCL-TypeD 3** CSI-RS (CSI) QCL-TypeA CSI-RS(CSI) QCL-TypeD 4* SS/PBCH Block* QCL-TypeA SS/PSCH Block* QCL-TypeD

In Table 10, * represents a configuration that can be applied before theTRS is configured. In this case, the configuration may be a valid QCLassumption rather than a TCI state.

In Table 10, ** represents that QCL parameters may not be directlyderived from CSI-RS(s) (CSI).

For the PDCCH DMRS, the UE may expect only the following three availableconfigurations of the higher-layer parameter TCI-State, while the fourthconfiguration (in the fourth row in the following two tables) is validby default, before a TRS is configured.

TABLE 11 Valid TCI state DL RS 2 qcl-Type2 Configuration DL RS 1qcl-Type1 (if configured) (if configured) 1 TRS QCL-TypeA TRS QCL-TypeD2 TRS QCL-TypeA CSl-RS (BM) QCL-TypeD 3** CSI-RS (CSI) QCL-TypeA CSI-RS(CSI) QCL-TypeD 4* SS/PBCH Block* QCL-TypeA SS/PBCH Block* QCL-TypeD

In Table 11, * represents a configuration that can be applied before theTRS is configured. In this case, the configuration may correspond to avalid QCL assumption rather than a TCI state.

In Table 11, ** represents that QCL parameters may not be directlyderived from CSI-RS(s) (CSI).

1.6. Channel State Information Reference Signal (CSI-RS)

A mobile communication system according to the present disclosure uses amethod for increasing data transmission/reception efficiency by adoptingmultiple transmission antennas and multiple reception antennas forpacket transmission. When data is transmitted/received through multipleinput/output antennas, channel states between the transmission antennasand the reception antennas should be detected to accurately receive thesignal. Therefore, each transmission antenna may have an individual RS.An RS for CSI feedback may be defined as a CSI-RS.

The CSI-RS includes zero power (ZP) CSI-RS and non-zero power (NZP)CSI-RS. The ZP CSI-RS and the NZP CSI-RS may be defined as follows.

-   -   The NZP CSI-RS may be configured by an NZP-CSI-RS-Resource        information element (LE) or a CSI-RS-Resource-Mobility field in        a CSI-RS-ResourceConfigMobility IE. The NZP CSI-RS may be        defined based on the sequence generation and resource mapping        method defined in 3GPP TS 38.211.    -   The ZP CSI-RS may be configured by a ZP-CSI-RS-Resource IE. The        UE may assume that resources configured for the ZP CSI-RS are        not used for PDSCH transmission. The UE performs the same        measurement/reception on channels/signals except PDSCHs        regardless of whether they collide with the ZP CSI-RS or not

Positions at which the CSI-RS is mapped in a slot may be dynamicallydetermined by the number of CSI-RS ports, a CSI-RS density, a codedivision multiplexing (CDM) type, and a higher-layer parameter (e.g.,firstOFDMSymbolInTimeDomain, firstOFDMSymbolInTimeDomain2, and so on).

1.7. Demodulation Reference Signal (DMRS)

In the NR system to which the present disclosure is applicable, a DMRSmay be transmitted and received in a front-loaded structure.Alternatively, an additional DMRS may be transmitted and received inaddition to the front-loaded DMRS.

The front-loaded DMRS may support fast decoding. The first OFDM symbolin which the front-loaded DMRS is carried may be determined as the third(e.g., 1=2) or fourth (e.g., 1=3) OFDM symbol. The first OFDM symbolposition may be indicated by a PBCH.

The number of OFDM symbols in which the front-loaded DMRS is occupiedmay be indicated by a combination of DCI and radio resource control(RRC) signaling.

The additional DMRS may be configured for a high-speed UE. Theadditional DMRS may be positioned in the middle/last symbol(s) in aslot. If one front-loaded DMRS is configured, the additional DMRS may beallocated to 0 to 3 OFDM symbols. If two front-loaded DMRS symbols areconfigured, the additional DMRS may be allocated to 0 to 2 OFDM symbols.

The front-loaded DMRS may be divided into two types and one of the twotypes may be indicated through higher layer signaling (e.g., RRCsignaling).

In the present disclosure, two DMRS configuration types may be applied.Among of the two DMRS configuration types, a DMRS configuration typethat is actually configured for a UE may be indicated by higher layersignaling (e.g., RRC signaling).

DMRS configuration type 1 may be subdivided as follows depending on thenumber of OFDM symbols allocated for the front-loaded DMRS.

DMRS configuration type 1 and number of OFDM symbols to which thefront-loaded DMRS is allocated=1

Up to 4 ports (e.g., P0 to P3) may be multiplexed based on length-2frequency code division multiplexing (F-CDM) and frequency divisionmultiplexing (FDM) schemes. RS density may be set to 6 REs per port in aresource block (RB).

DMRS configuration type 1 and number of OFDM symbols to which thefront-loaded DMRS is allocated=2

Up to 8 ports (e.g., P0 to P7) may be multiplexed based on length-2F-CDM, length-2 time CDM (T-CDM), and FDM schemes. If presence of aPT-RS is configured by higher layer signaling, T-CDM may be fixed to [11]. RS density may be set to 12 REs per port in the RB.

DMRS configuration type 2 may be classified as follows according to thenumber of OFDM symbols to which the front-loaded DMRS is allocated.

DMRS configuration type 2 and number of OFDM symbols to which thefront-loaded DMRS is allocated=1

Up to 6 ports (e.g., P0 to P5) may be multiplexed based on length-2F-CDM and FDM schemes. RS density may be set to 4 REs per port in theRB. DMRS configuration type 2 and number of OFDM symbols to which thefront-loaded DMRS is allocated=2

Up to 12 ports (e.g., P0 to P11) may be multiplexed based on length-2F-CDM, length-2 T-CDM, and FDM schemes. If presence of the PT-RS isconfigured by higher layer signaling, T-CDM may be fixed to [1 1]. RSdensity may be set to 8 REs per port in the RB.

FIGS. 6A and 6B are diagrams schematically illustrating an example of afront loaded DMRS of a first DMRS configuration type applicable to thepresent disclosure.

More specifically, FIG. 6A illustrates a front-loaded DMRS with onesymbol and FIG. 6B illustrates a front-loaded DMRS with two symbols.

In FIGS. 6A and 6B, A represents a DMRS offset value on the frequencyaxis. In this case, DMRS ports having the same DMRS offset A may besubjected to code division multiplexing in the frequency domain (CDM-F)or code division multiplexing in the time domain (CDM-T). In addition,DMRS ports having different DMRS offsets Δ may be subjected to CDM-F.

According to the present disclosure, CDM-F may be applied based onw_(f)(k′) of the following table, and CDM-T may be applied based onw_(t)(l′) of the following table. k′ and l′ are parameters thatdetermine the index of a subcarrier to which the DMRS is mapped, whichmay have a value 0 or 1. DMRSs corresponding to respective DMRS portsmay be grouped into CDM groups listed in the following table.

Table 12 lists parameters for a first DMRS configuration type for thePDSCH, and Table 13 lists parameters for a second DMRS configurationtype for the PDSCH.

TABLE 12 CDM group w_(f) (k′) w_(l) (l′) p λ Δ k′ = 0 k′ = 1 l′ = 0 l′ =1 1000 0 0 +1 +1 +1 +1 1001 0 0 +1 −1 +1 +1 1002 1 1 +1 +1 +1 +1 1003 11 +1 −1 +1 +1 1004 0 0 +1 +1 +1 −1 1005 0 0 +1 −1 +1 −1 1006 1 1 +1 +1+1 −1 1007 1 1 +1 −1 +1 −1

TABLE 13 CDM group w_(f) (k′) w_(l) (l′) p λ Δ k′ = 0 k′ = 1 l′ = 0 l′ =1 1000 0 0 +1 +1 +1 +1 1001 0 0 +1 −1 +1 +1 1002 1 2 +1 +1 +1 +1 1003 12 +1 −1 +1 +1 1004 2 4 +1 +1 +1 +1 1005 2 4 +1 −1 +1 +1 1006 0 0 +1 +1+1 −1 1007 0 0 +1 −1 +1 −1 1008 1 2 +1 +1 +1 −1 1009 1 2 +1 −1 +1 −11010 2 4 +1 +1 +1 −1 1011 2 4 +1 −1 +1 −1

The UE may obtain DMRS port configuration information configured by theBS from DCI. For example, the UE may obtain the DMRS port configurationinformation from an antenna ports field of DCI format 1_1 based on aDMRS configuration type configured for the UE (e.g., a first DMRSconfiguration type (dmrs-Type=1) or a second DMRS configuration type(dmrs-Type=2)), and the maximum number of OFDM symbols for a DL frontloaded DMRS (e.g., maxLength=1 or maxLength=2). More specifically, Table14 illustrates DMRS port configuration information according to thevalue of the antenna ports field, when (dmrs-Type=1 and maxLength=1) isconfigured for the UE, and Table 15 illustrates DMRS port configurationinformation according to the value of the antenna ports field, when(dmrs-Type=1 and maxLength=2) is configured for the UE. Table 16illustrates DMRS port configuration information according to the valueof the antenna ports field, when (dmrs-Type=2 and maxLength=1) isconfigured for the UE, and Table 17 illustrates DMRS port configurationinformation according to the value of the antenna ports field, when(dmrs-Type=2 and maxLength=2) is configured for the UE.

TABLE 14 One Codeword: Codeword 0 enabled, Codeword 1 disabled Number ofDMRS CDM group(s) DMRS Value without data port(s) 0 1 0 1 1 1 2 1 0, 1 32 0 4 2 1 5 2 2 6 2 3 7 2 0, 1 8 2 2, 3 9 2 0-2 10 2 0-3 11 2 0, 2 12-15Reserved Reserved

TABLE 15 One Codeword: Two Codewords: Codeword 0 enabled, Codeword 0enabled, Codeword 1 disabled Codeword 1 enabled Number of Number of DMRSCDM Number of DMRS CDM Number of group(s) DMRS front-load group(s) DMRSfront-load Value without data port(s) symbols Value without data port(s)symbols 0 1 0 1 0 2 0-4 2 1 1 1 1 1 2 0, 1, 2, 3, 4, 6 2 2 1 0, 1 1 2 20, 1, 2, 3, 4, 5, 6 2 3 2 0 1 3 2 0, 1, 2, 3, 4, 5, 6, 7 2 4 2 1 1 4-31reserved reserved reserved 5 2 2 1 6 2 3 1 7 2 0, 1 1 8 2 2, 3 1 9 2 0-21 10 2 0-3 1 11 2 0, 2 1 12 2 0 2 13 2 1 2 14 2 2 2 15 2 3 2 16 2 4 2 172 5 2 18 2 6 2 19 2 7 2 20 2 0, 1 2 21 2 2, 3 2 22 2 4, 5 2 23 2 6, 7 224 2 0, 4 2 25 2 2, 6 2 26 2 0, 1, 4 2 27 2 2, 3, 6 2 28 2 8, 1, 4, 5 229 2 2, 3, 6, 7 2 30 2 8, 2, 4, 6 2 31 Reserved Reserved Reserved

TABLE 16 One codeword: Two codewords: Codeword 0 enabled, Codeword 0enabled, Codeword 1 disabled Codeword 1 disabled Number of Number ofDMRS CDM DMRS CDM group(s) DMRS group(s) DMRS Value without data port(s)Value without data port(s) 0 1 0 0 3 0-4 1 1 1 1 3 0-5 2 1 0, 1 2-31reserved reserved 3 2 0 4 2 1 5 2 2 6 2 3 7 2 0, 1 8 2 2, 3 9 2 0-2 10 20-3 11 3 0 12 3 1 13 3 2 14 3 3 15 3 4 16 3 5 17 3 0, 1 18 3 2, 3 19 34, 5 20 3 0-2 21 3 3-5 22 3 0-3 23 2 0, 2 24-31 Reserved Reserved

TABLE 17 One codeword: Two Codewords: Codeword 0 enabled, Codeword 0enabled, Codeword 1 disabled Codeword 1 enabled Number of Number of DMRSCDM Number of DMRS CDM Number of groupfs} DMRS front-load group(s) DMRSfront-load Value without data port(s) symbols Value without data port(s)symbols 0 1 0 1 0 3 0-4 1 1 1 1 1 1 3 0-5 1 2 1 0, 1 1 2 2 0, 1, 2, 3, 62 3 2 0 1 3 2 0, 1, 2, 3, 6, 8 2 4 2 1 1 4 2 0, 1, 2, 3, 6, 7, 8 2 5 2 21 5 2 0, 1, 2, 3, 6, 7, 8, 9 2 6 2 3 1 6-63 Reserved Reserved Reserved 72 0, 1 1 8 2 2, 3 1 9 2 0-2 1 10 2 0-3 1 11 3 0 1 12 3 1 1 13 3 2 1 14 33 1 15 3 4 1 16 3 5 1 17 3 0, 1 1 18 3 2, 3 1 19 3 4, 5 1 20 3 0-2 1 213 3-5 1 22 3 0-3 1 23 2 0, 2 1 24 3 0 2 25 3 1 2 26 3 2 2 27 3 3 2 28 34 2 29 3 5 2 30 3 6 2 31 3 7 2 32 3 8 2 33 3 9 2 34 3 10 2 35 3 11 2 363 0, 1 2 37 3 2, 3 2 38 3 4, 5 2 39 3 6, 7 2 40 3 8, 9 2 41 3 10, 11 242 3 0, 1, 6 2 43 3 2, 3, 8 2 44 3  4, 5, 10 2 45 3 0, 1, 6, 7 2 46 3 2,3, 8, 9 2 47 3 4, 5, 10, 11 2 48 1 0 2 49 1 1 2 50 1 6 2 51 1 7 2 52 10, 1 2 53 1 6, 7 2 54 2 0, 1 2 55 2 2, 3 2 56 2 6, 7 2 57 2 8, 9 2 58-63Reserved Reserved Reserved

The UE may receive the DMRS according to a condition as follows.

For DMRS configuration type 1,

-   -   when one codeword is scheduled for the UE, and DCI indicating        one of {2, 9, 10, 11, 30} as an index related to antenna port        mapping (e.g., an index in Table 14 or Table 15) is allocated to        the UE, or    -   when two codewords are scheduled for the UE,

the UE may receive the DMRS on the assumption that none of the remainingorthogonal antenna ports are associated with a PDSCH transmission toanother UE.

For DMRS configuration type 2,

-   -   when one codeword is scheduled for the UE, and DCI indicating        one of {2, 10, 23} as an index related to antenna port mapping        (e.g., an index in Table 14 or Table 15) is allocated to the UE,        or    -   when two codewords are scheduled for the UE,

the UE may receive the DMRS on the assumption that none of the remainingorthogonal antenna ports are associated with a PDSCH transmission toanother UE.

1.8. Codeword

In the present disclosure, the BS may configure the maximum number ofcodewords scheduled by one DCI for the UE by higher-layer signaling. Forexample, the BS may set the maximum number of codewords scheduled by oneDCI to 1 or 2 for the UE based on the higher-layer parametermaxNrofCodeWordsScheduledByDCI (having a value n1 or n2). Thehigher-layer parameter maxNrofCodeWordsScheduledByDCI may be included inthe higher-layer parameter PDSCH-Config.

Referring to Rel-15 TS 38.212, DCI format 1_1 may be configured asdescribed in the following table according to the higher-layer parametermaxNrofCodeWordsScheduledByDCI.

TABLE 18 For transport block 1: Modulation and coding scheme - 5 bitsNew data indicator - 1 bit Redundancy version - 2 bits For transportblock 2 (only present if maxNorfCodeWordsScheduledByDCI equals 2):Modulation and coding scheme - 5 bits New data indicator - 1 bitRedundancy version - 2 bits

Therefore, the NDI, MCS, and RV of CW #0 may be configured/indicatedbased on the NDI, MCS, and RV for TB 1 in the DCI. Likewise, the NDI,MCS, and RV of CW #1 may be configured/indicated based on the NDI, MCS,and RV for TB 2 in the DCI.

Additionally, when (i) a bandwidth part indicator field indicates abandwidth part other than an active bandwidth part, (ii) thehigher-layer parameter maxNrofCodeWordsScheduledByDCI for the indicatedbandwidth part is set to 2, and (iii) the higher-layer parametermaxNrofCodeWordsScheduledByDCI for the active bandwidth part is set to1, the UE may assume that the MCS, NDI, and RV fields of TB 2 arezero-padded in interpreting the MCS, NDI, and RV fields of TB 2. In thiscase, the UE may ignore the MCS, NDI, and RV fields of TB 2 for theindicated bandwidth part.

Further, when the higher-layer parameter maxNrofCodeWordsScheduledByDCIindicates that a 2-codeword transmission is enabled, one of two TBs (orcodewords) may be enabled or disabled in the following method.

More specifically, when the higher-layer parametermaxNrofCodeWordsScheduledByDCI indicates that a 2-codeword transmissionis enabled, one of the two TBs may be disabled, when for a RBcorresponding to DCI format 1_1, (i) the MCS value is 26 (i.e., IMCS=26)and (ii) the RV value is 1 (i.e., rvid=1). When both of the TBs areenabled, TB 1 and TB 2 may be mapped to codeword 0 and codeword 1,respectively. When only one TB is enabled, the active TB may always bemapped to the first codeword (i.e., codeword 0).

1.9. Time/Frequency Resource Allocation Cases Applicable to the PresentDisclosure

In the present disclosure, time/frequency (T/F) resources of PDSCHs(e.g., PDSCH #0 and PDSCH #1) transmitted from different transmissionand reception points (TRPs) (beams or panels) may overlap with eachother in various manners. Cases in which T/F resources are overlappedmay include all five cases illustrated in FIG. 7.

FIG. 7 is a diagram illustrating exemplary cases in which two PDSCHs areoverlapped with each other in time and/or frequency resources, which areapplicable to the present disclosure.

As illustrated in FIG. 7, two PDSCHs may be partially overlapped witheach other (e.g., case #1 to case #3) or may be overlapped with eachother in one of the time domain and the frequency domain (e.g., case #4and case #5). In case #1/#2/#3 of FIG. 7, the two PDSCHs are (partially)overlapped with each other in both time and frequency. In case #4 ofFIG. 7, the two PDSCHs are not overlapped only on the time axis. In case#5 of FIG. 7, the two PDSCHs are overlapped on the time axis but not onthe frequency axis.

1.10. Single PDCCH System

FIG. 8 is a simplified diagram illustrating a single PDCCH systemoperation applicable to the present disclosure.

In FIG. 8, it is assumed that two TRPs TRP #1 and TRP #2 transmit PDSCH#1 and PDSCH #2 to one UE, respectively. In the following description,an operation of scheduling a plurality of PDSCHs by one PDCCH isreferred to as a single PDCCH system or a single PDCCH operation, asillustrated in FIG. 8. In other words, a single PDCCH may mean a PDCCHthat schedules a plurality of PDSCHs (for different TRPs).

While the following description is given in the context of two TRPs asan example of a plurality of TRPs, for convenience, the same operationmay be equally applied to three or more TRPs according to someembodiments. In other words, a single PDCCH may include a PDCCH thatschedules PDSCHs for three or more TRPs in the present disclosure.

According to the single PDCCH system, even though the UE receives PDSCHsfrom different TRPs, the UE may obtain scheduling information for theplurality of PDSCHs by receiving one PDCCH. Accordingly, the PDCCHreception complexity of the UE may be lowered.

Compared to the single PDCCH system, the UE may receive two PDSCHs onlywhen receiving two PDCCHs in a multi-PDCCH system or multi-PDCCHoperation in which two TRPs transmit the PDCCHs, each scheduling one ofthe PDSCHs, PDSCH #1 and PDSCH #2. In the single PDCCH system or singlePDCCH operation, the UE may receive two PDSCHs by successfully receivingonly one PDCCH, thereby minimizing performance degradation caused byPDCCH miss detection.

In FIG. 8, TRP #1 and/or TRP #2 may transmit the PDCCH that schedulesPDSCH #1 and PDSCH #2 to the UE.

1.11. Non-Coherent Joint Transmission (NC-JT)

In the present disclosure, a signal transmission method based on(partial) overlap between the time resources of PDSCHs transmitted bydifferent TRPs (or beams) (case #5 in FIG. 7) or (partial) overlapbetween the time and frequency resources of PDSCHs transmitted bydifferent TRPs (or beams) (cases #1, #2, and #3 in FIG. 7) is referredto as NC-JT.

In the present disclosure, a single DCI-based NC-JT may refer to anNC-JT operation when PDSCHs transmitted from different TRPs (or beams)are scheduled by one DCI. For example, the single DCI-based NC-JT mayinclude an NC-JT operation when both of PDSCH #1 and PDSCH #2 arescheduled by DCI #1.

In the present disclosure, multi-DCI-based NC-JT is an NC-JT operationwhen each of PDSCHs transmitted from different TRPs (or beams) isscheduled by one DCI. For example, the multi-DCI-based NC-JT may includean NC-JT operation when PDSCH #1 and PDSCH #2 are simultaneouslyscheduled by DCI #1 and DCI #2, respectively.

In the present disclosure, two types of NC-JT may be defined dependingon whether different TRPs transmit independent layers or common layers.

In the present disclosure, when it is said that “layers areindependent”, this may imply that when TRP #A transmits a signal inthree layers and TRP #B transmits a signal in four layers, the UEexpects to receive signals in seven layers in total.

On the other hand, in the present disclosure, when it is said that“layers are common”, this may imply that when TRP #A transmits a signalin three layers and TRP #B transmits a signal in three layers, the UEexpects to receive signals in three layers in total.

In the present disclosure, to distinguish the above two operations,NC-JT based on the former operation is referred to as “NC-JT withindependent layer (IL)”, and NC-JT based on the latter operation isreferred to as “NC-JT with common layer (CL)”.

While various operation examples are described based on the “NC-JT withIL” operation (or mode) in the present disclosure, the operationexamples may be extended to operation examples based on the “NC-JT withCL” operation (or mode).

1.12. HARQ Process

DCI transmitted from the BS to the UE may include an “HARQ processnumber” field configured in 4 bits. Based on an HARQ process numberindicated by the “HARQ process number” field in the DCI, the UE maydistinguish/identify a PDSCH among previously transmitted PDSCHs, forwhich a PDSCH scheduled by the DCI is a retransmission.

1.13. Determination of Modulation Order and Target Code Rate

In the present disclosure, a PDSCH may be scheduled by a PDCCH (e.g.,DCI format 1_0 or DCI format 1_1) having a cyclic redundancy check (CRC)scrambled with a cell radio network temporary identifier (C-RNTI), amodulation coding scheme cell RNTI (MCS-C-RNTI), a temporary cell RNTI(TC-RNTI), a configured scheduling RNTI (CS-RNTI), a system informationRNTI (SI-RNTI), a random access RNTI (RA-RNTI), or a paging RNTI(P-RNTI). Alternatively, the PDSCH may be scheduled based on a PDSCHconfiguration (SPS-config) provided by a higher layer, withouttransmission of a corresponding PDCCH. A modulation order and a targetcode rate for the PDSCH may be determined/configured as follows.

(1) When (i) a higher-layer parameter mcs-Table provided by PDSCH-Configis set to “qam256” and (ii) the PDSCH is scheduled by (a PDCCHincluding) DCI format 1_1 with a CRC scrambled with a C-RNTI,

-   -   the UE may determine a modulation order Q_(m) and a target code        rate R for the PDSCH based on an MCS value (e.g., I_(MCS)) and        Table 20.

(2) Or when (i) an MCS-C-RNTI is not configured for the UE, (ii) thehigher-layer parameter mcs-Table provided by PDSCH-Config is set to“qam64LowSw”, and (iii) the PDSCH is scheduled by a PDCCH with a CRCscrambled with a C-RNTI in a UE-specific search space,

-   -   the UE may determine a modulation order Q_(m) and a target code        rate R for the PDSCH based on an MCS value (e.g., I_(MCS)) and        Table 21.

(3) Or when (i) an MCS-C-RNTI is configured for the UE and (ii) thePDSCH is scheduled by a PDCCH with a CRC scrambled with the MCS-C-RNTI,

-   -   the UE may determine a modulation order Q_(m) and a target code        rate R for the PDSCH based on an MCS value (e.g., I_(MCS)) and        Table 21.

(4) Or when (i) the higher-layer parameter mcs-Table provided bySPS-Config is not configured for the UE, and (ii) the higher-layerparameter mcs-Table provided by PDSCH-Config is set to “qam265”,

-   -   when the PDSCH is scheduled by (a PDCCH including) DCI format        1_1 with a CRC scrambled with a CS-RNTI, or    -   when the PDSCH is scheduled by SPS-config without transmission        of a corresponding PDCCH,        -   the UE may determine a modulation order Q_(m) and a target            code rate R for the PDSCH based on an MCS value (e.g.,            I_(MCS)) and Table 20.

(5) Or when (i) the higher-layer parameter mcs-Table provided bySPS-Config is set to “qam64LowSE”,

-   -   when the PDSCH is scheduled by a PDCCH with a CRC scrambled with        a CS-RNTI, or    -   when the PDSCH is scheduled by SPS-config without transmission        of a corresponding PDCCH,    -   the UE may determine a modulation order Q_(m) and a target code        rate R for the PDSCH based on an MCS value (e.g., I_(MCS)) and        Table 21.

(6) Or the UE may determine a modulation order Q_(m) and a target coderate R for the PDSCH based on an MCS value (e.g., I_(MCS)) and Table 19.

TABLE 19 MCS Index Modulation Order Target code Rate Spectral I_(MCS)Q_(m) R × [1024] efficiency 0 2 120 0.2344 1 2 157 0.3066 2 2 193 0.37703 2 251 0.4902 4 2 308 0.6016 5 2 379 0.7402 6 2 449 0.8770 7 2 5261.0273 8 2 602 1.1758 9 2 679 1.3262 10 4 340 1.3281 11 4 378 1.4766 124 434 1.6953 13 4 490 1.9141 14 4 553 2.1602 15 4 616 2.4063 16 4 6582.5703 17 6 438 2.5664 18 6 466 2.7305 19 6 517 3.0293 20 6 567 3.322321 6 616 3.6094 22 6 666 3.9023 23 6 719 4.2129 24 6 772 4.5234 25 6 8224.8164 26 6 873 5.1152 27 6 910 5.3320 28 6 948 5.5547 29 2 reserved 304 reserved 31 6 reserved

TABLE 20 MCS index Modulation Order Target code Rate Spectral I_(MCS)Q_(m) R × [1024] efficiency 0 2 120 0.2344 1 2 193 0.3770 2 2 308 0.60163 2 449 0.8770 4 2 602 1.1758 5 4 378 1.4766 6 4 434 1.6953 7 4 4901.9141 8 4 553 2.1602 9 4 616 2.4063 10 4 658 2.5703 11 6 466 2.7305 126 517 3.0293 13 6 567 3.3223 14 6 616 3.6094 15 6 666 3.9023 16 6 7194.2129 17 6 772 4.5234 18 6 822 4.8164 19 6 873 5.1152 20 8 682.5 5.332021 8 711 5.5547 22 8 754 5.8906 23 8 797 6.2266 24 8 841 6.5703 25 8 8856.9141 26 8 916.5 7.1602 27 8 948 7.4063 28 2 reserved 29 4 reserved 306 reserved 31 8 reserved

TABLE 21 MCS Index Modulation Order Target code Rate Spectral I_(MCS)Q_(m) R × [1024] efficiency 0 2 30 0.0586 1 2 40 0.0781 2 2 50 0.0977 32 64 0.1250 4 2 78 0.1523 5 2 99 0.1934 6 2 120 0.2344 7 2 157 0.3066 82 193 0.3770 9 2 251 0.4902 10 2 308 0.6016 11 2 379 0.7402 12 2 4490.8770 13 2 526 1.0273 14 2 602 1.1758 15 4 340 1.3281 16 4 378 1.476617 4 434 1.6953 18 4 490 1.9141 19 4 553 2.1602 20 4 616 2.4063 21 6 4382.5664 22 6 466 2.7305 23 6 517 3.0293 24 6 567 3.3223 25 6 616 3.609426 6 666 3.9023 27 6 719 4.2129 28 6 772 4.5234 29 2 reserved 30 4reserved 31 6 reserved

1.14. Transport Block Size Determination

Based on section 5.1.3.2 in the standard specification 3GPP TS 38.214,the size of a transport block between the UE and the BS according to thepresent disclosure may be determined. More specifically, the transportblock size may be determined as follows.

When the higher layer parameter maxNrofCodeWordsScheduledByDCI indicatesthat transmission of two codewords is enabled, if (i) the value ofI_(MCS) is 26 and (ii) the value of rv_(id) is 1 for the correspondingtransport block, the corresponding transport block may be disabled byDCI format 1_1. When both transport blocks are enabled, transport block1 and transport block 2 may be mapped to codeword 0 and codeword 1,respectively. When only one transport block is enabled, the enabledtransport block may always be mapped to the first codeword (e.g.,codeword 0).

For the FDSCH allocated by DCI format 1_0 or DCI format 1_1 (or a PDCCHincluding the same) CRC scrambled by C-RNTI, MCS-C-RNTI, TC-RNTI,CS-RNTI or SI-RNTI, when (i) Table 19 is used and I_(MCS) is greaterthan or equal to 0 and less than or equal to 27, or (ii) Table 18 orTable 20 is used and I_(MCS) is greater than or equal to 0 and less thanor equal to 27, the UE may determine the transport block size (TBS) asfollows, except for the case the transport block in DCI format 1_1 isdisabled.

(1) The UE first determines the number of REs (e.g., N_(RE)) in theslot.

-   -   The UE first determines the number of REs (e.g., N′_(RE))        allocated for the PDSCH in the PRB, based on the following        equation.

N _(RE) ′=N _(sc) ^(RB) ·N _(symb) ^(sh) −N _(DMRS) ^(PRB) −N _(oh)^(PRB)   [Equation 1]

In the equation above, N_(sc) ^(RB)=12 denotes the number of subcarriersin a PRB, N_(symb) ^(sh) denotes the number of symbols included in thePDSCH allocation in the slot, N_(DMRS) ^(PRB) denotes the number of REsfor DMRS for each PRB in a scheduled interval including the overhead ofthe DMRS CDM group without data, as indicated by DCI format 1_1 ordetermined according to characteristics of DCI format 1_0, and N_(oh)^(PRB) denotes the overhead set by the higher layer parameter xOverheadin the higher layer parameter PDSCH-ServingCellConfig. When the higherlayer parameter xOverhead is not configured in the higher layerparameter PDSCH-ServingCellConfig (the corresponding value may be set to0, 6, 12 or 18), N_(oh) ^(PRB) is set to 0. When the PDSCH is scheduledby the PDCCH CRC scrambled by SI-RNTI, RA-RNTI or P-RNTI, N_(oh) ^(PRB)may be assumed to be 0.

-   -   The UE may determine N_(RE), the total number of REs allocated        for the PDSCH, based on the following equation.

N _(RE)=min(156,N _(RE)′)·n _(PRB)  [Equation 2]

In the equation above, n_(PRB) denotes the total number of PRBsallocated for the UE.

(2) N_(info), the intermediate number of information bits may beacquired based on the following equation.

N _(info) =N _(RE) ·R·Q _(m·υ)  [Equation 3]

In the equation above, R denotes a target code rate determined by theMCS field, Q_(m) denotes a modulation order determined by the MCS field,and υ denotes the number of layers.

When the size of N_(info) is less than or equal to 3824, step 3 may beused as a next step in determining the TBS. Conversely, when the size ofN_(info) is greater than 3824, step 4 may be used as a next step indetermining the TBS.

(3) If the size of N_(info) is 3824 or less, TBS may be determined asfollows:

-   -   N′_(info), which is a quantized intermediate number of        information bits, may be set to satisfy the following equation.

$\begin{matrix}{N_{\inf\; o}^{\prime} = {\max\left( {{24},{2^{n} \cdot \left\lfloor \frac{N_{\inf\; o}}{2^{n}} \right\rfloor}} \right)}} & \left\lbrack {{Equation}\mspace{14mu} 4} \right\rbrack\end{matrix}$

In the equation above, n may satisfy n=max(3,└log₂(N_(info))┘−6).

-   -   Based on the table below, the nearest TBS that is not less than        N′_(info) is found.

TABLE 22 Index TBS 1 24 2 32 3 40 4 48 5 56 6 64 7 72 8 80 9 88 10 96 11104 12 112 13 120 14 128 15 136 16 144 17 152 18 160 19 168 20 176 21184 22 192 23 208 24 224 25 240 26 256 27 272 28 288 29 304 30 320 31336 32 352 33 368 34 384 35 408 36 432 37 456 38 480 39 504 40 528 41552 42 576 43 608 44 640 45 672 46 704 47 736 48 768 49 808 50 848 51888 52 928 53 984 54 1032 55 1064 56 1128 57 1160 58 1192 59 1224 601256 61 1288 62 1320 63 1352 64 1416 65 1480 66 1544 67 1608 68 1672 691736 70 1800 71 1864 72 1928 73 2024 74 2088 75 2152 76 2216 77 2280 782408 79 2472 80 2536 81 2600 82 2664 83 2728 84 2792 85 2856 86 2976 873104 88 3240 89 3368 90 3496 91 3624 92 3752 93 3824

(4) When the size of N_(info) exceeds 3824, the TBS may be determined asfollows:

-   -   N′_(info), which is a quantized intermediate number of        information bits, may be set to satisfy the following equation.

$\begin{matrix}{N_{\inf\; o}^{\prime} = {\max\left( {3840,{2^{n} \times {{round}\left( \frac{N_{\inf\; o} - {24}}{2^{n}} \right)}}} \right)}} & \left\lbrack {{Equation}\mspace{14mu} 5} \right\rbrack\end{matrix}$

In the equation above, n may satisfy n=└log₂ (N_(info)−24)┘−5.

-   -   When R is less than or equal to ¼, the TBS may be determined to        satisfy the following equation.

$\begin{matrix}{{T\; B\; S} = {{8 \cdot C \cdot \left\lceil \frac{N_{\inf\; o}^{\prime} + {24}}{8 \cdot C} \right\rceil} - {24}}} & \left\lbrack {{Equation}\mspace{14mu} 6} \right\rbrack\end{matrix}$

In the equation above, C may be set to satisfy

${C = \left\lceil \frac{N_{\inf\; o}^{\prime} + 24}{3816} \right\rceil}.$

-   -   Alternatively, when R is greater than ¼ and N′_(info) is greater        than 8424, the TBS may be determined to satisfy the following        equation.

$\begin{matrix}{{T\; B\; S} = {{8 \cdot C \cdot \left\lceil \frac{N_{\inf\; o}^{\prime} + 24}{8 \cdot C} \right\rceil} - {24}}} & \left\lbrack {{Equation}\mspace{14mu} 7} \right\rbrack\end{matrix}$

In the equation above, C may be set to satisfy

${C = \left\lceil \frac{N_{\inf\; o}^{\prime} + 24}{8424} \right\rceil}.$

-   -   Alternatively, the TBS may be determined to satisfy the        following equation.

$\begin{matrix}{{T\; B\; S} = {{8 \cdot \left\lceil \frac{N_{\inf\; o}^{\prime} + 24}{8} \right\rceil} - {24}}} & \left\lbrack {{Equation}\mspace{14mu} 8} \right\rbrack\end{matrix}$

Unlike the foregoing, when Table 19 is used, and I_(MCS) is greater thanor equal to 28 and less than or equal to 31, the TBS may be determinedas follows.

More specifically, in the above case, it may be assumed that the TBS isdetermined from the DCI transmitted on the latest PDCCH for an identicaltransport block using I_(MCS) having a value of 0 to 27. When (i) thereis no identical transport blocks using I_(MCS) having a value of 0 to27, and (ii) the initial PDSCH for the identical transport block issemi-persistently scheduled, the TBS may be determined from the latestsemi-persistent scheduling (SPS) allocation PDCCH.

Alternatively, it may be assumed that the TBS is determined from the DCItransmitted on the latest PDCCH for the identical transport block usingI_(MCS) having a value of 0 to 28. When (i) there is no identicaltransport blocks using I_(MCS) having a value of 0 to 28, and (ii) theinitial PDSCH for the identical transport block is semi-persistentlyscheduled, the TBS may be determined from the latest SPS allocationPDCCH.

The UE may not expect that the PDSCH allocated by the PDCCH CRCscrambled by SI-RNTI has a TBS exceeding the size of 2976 bits.

For the PDSCH allocated by DCI format 1_0 (or a PDCCH including thesame) CRC scrambled by P-RNTI or RA-RNTI, the TBS determination mayfollow steps 1 to 4 above with the following modification applied instep 2: In calculating N_(info), scaling that satisfies the followingequation is applied to N_(info). Here, the scaling factor is determinedbased on the TB scaling field in DCI disclosed in the table below.

N _(info) =S·N _(RE) ·R·Q _(m)·υ  [Equation 9]

TABLE 23 TB scaling field Scaling factor S 00 1 01 0.5 10 0.25 11

In addition to the NDI and HARQ process ID signaled on the PDCCH, theTBS determined as described above may be reported to a higher layer (inthe UE).

2. Example of Operations of UE and BS in the Present Disclosure

2.0. Definition

In the present disclosure, terms used to describe the present disclosuremay be defined as follows.

In the present disclosure, higher-layer signaling may include radioresource control (RRC) signaling and/or a medium access control(MAC)-control element (CE).

In the present disclosure, TRP (Transmission Reception Point) may bereplaced with beam.

In the present disclosure, the term “PDSCH repetition” may include (i)simultaneous transmission of PDSCHs in the same frequency resources ofthe same OFDM symbol(s) from a plurality of TRPs/beam(s), (ii)simultaneous transmission of PDSCHs in frequency resources partiallyoverlapped in the same OFDM symbol(s) from a plurality of TRPs/beam(s),or (iii) simultaneous transmission of PDSCHs in different frequencyresources of the same OFDM symbol(s) from a plurality of TRPs/beam(s)(e.g., cases #2 and #5 of FIG. 7). The term “PDSCH repetition” mayfurther include (iv) transmission of PDSCHs in partially overlappingOFDM symbols from a plurality of TRP/beam(s) or (v) alternative PDSCHtransmissions in different OFDM symbols from a plurality of TRP/beam(s)(e.g., cases #1, #3, and #4 of FIG. 7).

In the present disclosure, a precoding resource block group (PRG) maycorrespond to a resource block group (RBG) or an RB.

In the present disclosure, a plurality of codewords (CWs) generated fromthe same information sequence may be replaced with “a plurality of CWsgenerated from the same TB”. In this case, CW #0 and CW #1 maycorrespond to the same TB. However, DCI for CW #0 and CW #1 may includeNDIs, MCSs, and RVs which are different for each of TBs (e.g., TB #1 andTB #2). In this regard, based on the indexes CW #0 and CW #1, (i) theNDI, MCS, and RV for CW #0 in the DCI may indicate the NDI, MCS, and RVof TB 1, and (ii) the NDI, MCS, and RV for CW #1 in the DCI may indicatethe NDI, MCS, and RV of TB 2.

In the present disclosure, to indicate a plurality of TRPs/beams to theUE by DCI, the BS may use a TCI state including a plurality of RS sets(e.g., a TCI state including two RS sets to indicate two TRPs/beams). Inthis case, the RS sets may correspond to the TRPs/beams one to one.

Alternatively, to indicate a plurality of TRPs/beams to the UE by DCI,the BS may allocate/configure a plurality of TCI states to/for the UE.Each TCI state may include one RS set. In this case, the TCI states maycorrespond to the TRPs/beams one to one.

Accordingly, a method for indicating a plurality of TRPs/beams to a UEby a BS may refer to not only (i) a method for indicating a TCI stateincluding two RS sets to a UE by a BS (even though specifically notmentioned) but also (ii) a method for indicating two different TCIstates each including one RS set to a UE by a BS.

In the present disclosure, a beam may be replaced with a resource.

In the present disclosure, the NDI, and/or RV, and/or MCS of CW #1 (orTB #2) may represent the NDI of CW #1 (or TB #2), and/or the RV of CW #1(or TB #2), and/or the MCS of CW #1 (or TB #2).

Further, the BS and the UE proposed in the present disclosure mayperform the above-described operation examples alone or in combination.

In the following description, each operation example may be performed inthe same manner for a DL signal transmission and a UL signaltransmission. In other words, PDSCH may be replaced by PUSCH, TRP or BSmay be replaced by UE as a signal transmission entity, and UE may bereplaced by TRP or BS as a signal reception entity in the followingdescription.

2.1. Specific Example of Operations of UE and BS to Configure PDSCHRepetition from Multiple TRPs Based on Single PDCCH

FIG. 9 is a simplified diagram illustrating a configuration forreceiving PDSCHs from two TRPs/beam(s) by a UE.

In FIG. 9, when two CWs transmitted from two TRPs have been generatedfrom the same information sequence, the UE may soft-combine the two CWsto remarkably increase a reception success rate.

In FIG. 9, the two TRPs may transmit the signals in the same T/Fresources (e.g., overlapped PRGs) or in disjointed T/F resources (e.g.,disjoint PRGs).

The overlapped PRGs scheme may be advantageous in terms of throughputbecause a spatial multiplexing gain is maximized. However, because theUE should simultaneously receive the total sum of layers transmittedfrom the two TRPs, the receiver complexity of the UE may increase.Moreover, interference between different layers may degrade thereception performance of the UE. When the UE reports CSI, interferencebetween different TRPs should be additionally considered for the CSIreport.

In the disjoint PRGs scheme, two TRPs transmit PDSCHs in differentresources, thereby reducing a spatial multiplexing gain. Nonetheless,the UE may have reduced receiver complexity and increased receptionperformance.

In FIG. 9, one block may refer to one PRG unit. The disjoint PRGs schememay include the following three schemes illustrated in FIG. 9.

-   -   Localized PRGs: Each of two TRPs may transmit a PDSCH in a        (roughly) half of a bandwidth that the BS has        indicated/allocated to the UE by DCI. In this method, when the        BS has knowledge of CSI between each TRP and the UE, the BS may        control each TRP to transmit a PDSCH to the UE in optimal        resources by using the CSI.    -   Interleaved PRGs: Each of two TRPs may transmit a PDSCH by using        PRGs in an interleaved manner in a bandwidth that the BS has        indicated/allocated to the UE by DCI. In this method, when the        BS has no knowledge or inaccurate knowledge of CSI between each        TRP and the UE, the BS may maximize frequency diversity by        controlling each TRP to transmit a PDSCH by distributing the        PDSCH as much as possible within a given bandwidth.    -   TDMed PRGs: Two TRPs may transmit PDSCHs in different resources        which are multiplexed in time division multiplexing (TDM). In        this case, both of the TRPs may transmit the PDSCHs based on the        same bandwidth.

Now, a detailed description will be given of, when CWs generated fromthe same information sequence are transmitted by a plurality ofTRPs/beam(s) as described above, a configuration method for supportingthe transmission mode and a method for operating a UE/BS based on theconfiguration method.

2.1.1. Method for Configuring PDSCH Repetition Mode

2.1.1.1. First Method for Configuring PDSCH Repetition Mode

The BS may configure a PDSCH repetition mode (e.g., a mode in which CWsgenerated from the same information sequence are transmitted by aplurality of TRPs/beam(s)) for the UE by higher-layer signaling (e.g.,RRC signaling or a MAC-CE). For convenience of description, the PDSCHrepetition mode is referred to as “PDSCH-rep-mode”.

2.1.1.2. Second Method for Configuring PDSCH Repetition Mode

The UE may expect configuration of the PDSCH-rep-mode based ondetermination that at least one of the following conditions issatisfied.

-   -   The BS transmits/indicates DCI including a CRC scrambled with an        RNTI for the PDSCH-rep-mode to the UE.    -   DCI that the BS has transmitted/indicated to the UE        configures/indicates (i) a TCI state including two RS sets        or (ii) two TCI states each including one RS set.    -   The BS configures the PDSCH-rep-mode for the UE by higher-layer        signaling.

In the present disclosure, the RNTI for the PDSCH-rep-mode may be newlydefined or an RNTI defined in a legacy system (e.g., MCS-C-RNTI).

More specifically, the MCS-C-RNTI may be used for robust PDSCHtransmission. The UE may consider an MCS table designed to be relativelyrobust, based on the MCS-C-RNTI. When the MCS-C-RNTI defined in thelegacy system is used as the RNTI for the PDSCH-rep-mode, the BS mayperform (robust) PDSCH transmission to the UE in the PDSCH-rep-mode.

In a specific example, when the BS indicates/configures a TCI stateincluding two RS sets to/for the UE, the UE may expect that PDSCHs willbe transmitted by different TRPs/beam(s). As a consequence, when (i) aTCI state including two RS sets and (ii) the RNTI for the PDSCH-rep-mode(e.g., MCS-C-RNTI) are simultaneously indicated/configured, the UE mayexpect that the PDSC-rep-mode will be configured.

In another specific example, when a TCI state including two RS sets isindicated/configured to/for the UE configured with the PDSCH-rep-mode byhigher-layer signaling (e.g., RRC signaling), the UE may expect that thePDSCH-rep-mode will be configured.

2.1.2. Method for Dynamically Configuring Enable/Disable ofPDSCH-Rep-Mode

2.1.2.1. First Method for Configuring Enable/Disable of PDSCH-Rep-Mode

The UE configured with the PDSCH-rep-mode may expect that two CWsgenerated from the same information sequence will be transmitted bydifferent TRPs/beam(s), based on determination that two CWs are enabledby DCI received from the BS. When a TCI state indicates/configures aplurality of RS sets, the UE may expect that the RS sets are mapped tothe CWs in order.

For example, it is assumed that TCI state={RS set #0, RS set #1} and CW#0 and CW #1 are indicated/configured to/for the UE configured with thePDSCH-rep-mode. In this case, the UE may expect to receive CW #0 on abeam indicated by RS set #0 and CW #1 on a beam indicated by RS set #1.Herein, beam may be replaced by resource.

2.1.2.2. Second Method for Configuring Enable/Disable of PDSCH-Rep-Mode

The UE configured with the PDSCH-rep-mode may expect that only oneTRP/beam transmits one CW based on determination that only one CW isenabled by DCI received from the BS. Alternatively, the UE configuredwith the PDSCH-rep-mode may not expect that CWs generated from the sameinformation sequence are transmitted by a plurality of TRPs/beam(s),based on determination that only one CW is enabled by DCI received fromthe BS.

The method described above may be applied even to a UE for which anoperation mode (e.g., a general PDSCH transmission mode for, forexample, a PDSCH scheduled by DCI including CRC scrambled with C-RNTI)other than the PDSCH-rep-mode is configured.

2.1.3. Method for Dynamically Configuring Mapping Relationship BetweenTwo CWs and Two RS Sets

2.1.3.1. First Method for Configuring Mapping Relationship

The UE configured with the PDSCH-rep-mode may determine/assume a mappingrelationship between two CWs and two RS sets, based on fields (e.g.,NDI, MCS, and RV) for TB #2 (or transport block 2) in received DCI.

When the BS is capable of dynamically indicating/configuring arelationship between two CWs and two RS sets to/for the UE, fields(e.g., at least one of the NDI, MCS, or RV field) for TB #2 may be usedfor other purposes (not for TB #2).

2.1.3.2. Second Method for Configuring Mapping Relationship

The UE configured with the PDSCH-rep-mode may expect to receive a PDSCHthrough one of TRPs/beams corresponding to two RS sets, respectively,based on a specific inactive CW (e.g., CW #0 or CW #1). Herein, a validRS set may be determined based on (i) an active TB, (ii) DCI fields(e.g., NDI, MCS, and RV) for the inactive TB, or (iii) DCI fields (e.g.,NDI, MCS, and RV) for TB #2 (or TB #1).

The above configuration method may configure which RS set transmits onevalid CW in the method for dynamically configuring enable/disable ofPDSCH-rep-mode described in section 2.1.2. Additionally, the methoddescribed above may be applied even to a UE for which an operation mode(e.g., a general PDSCH transmission mode for, for example, a PDSCHscheduled by DCI including CRC scrambled with C-RNTI) other than thePDSCH-rep-mode is configured.

In a specific example, it is assumed that the BS configures/indicatesTCI state={RS set #0, RS set #1} for/to the UE. The UE may assume/expectthat CW #0 and CW #1 are received through beams/TRPs indicated by RS set#0 and RS set #1, respectively.

On the above assumption, when CW #1 is disabled (i.e., the MCS field forCW #1 (or TB #2) is set to 26 and the RV field for CW #1 (or TB #2) isset to 1), CS #0 may be transmitted through a beam indicated by RS set#0. In contrast, CW #1 may not be transmitted through a beam indicatedby RS set #1.

On the contrary, when CW #0 is disabled, CW #1 may be transmittedthrough the beam indicated by RS set #1, and CW #0 may not betransmitted through the beam indicated by RS set #0.

In another specific example, it is assumed that the BSindicates/configures TCI state={RS set #0, RS set #1} to/for the UE andCW #1 is disabled. When the NDI field for CW #1 (or TB #2) is set to 0,CW #0 may be transmitted through the beam indicated by RS set #0. On theother hand, the UE may not expect a DL signal to be transmitted in RSset #1.

When the NDI field is set to 1, CW #0 may be transmitted through thebeam indicated by RS set #1. On the other hand, the UE may not expect aDL signal to be transmitted in RS set #0.

According to the above examples, using a TCI state including two RSsets, the BS may indicate/configure so that only TRP/beam correspondingto a specific RS set, such as dynamic point selection (DPS), transmits aPDSCH. For example, when TCI state #0={RS set #0} and TCI state #1={RSset #1}, and TCI state #2={RS set #0, RS set #1}, the BS may configureonly TCI state #2 for the UE. Subsequently, the BS may implement TCIstate #0 and TCI state #1 by enabling or disabling a CW (or TB)indicated/configured to/for the UE. Accordingly, the total number of TCIstates that the BS may configure for the UE may be decreased.

However, according to the 5G system, when the rank of a beam indicatedby one RS set is 5 or greater, two CWs should be transmitted in thesingle RS set. According to the above examples, it may be difficult toconfigure/indicate this case for/to the UE. That is, to implement thiscase, the total TC states that the BS may configure for the UE shouldinclude all of TCI state #0={RS set #0}, TCI state #1={RS set #1}, andTCI state #2={RS set #0, RS set #1}.

2.1.3.3. Third Method for Configuring Mapping Relationship

The UE configured with the PDSCH-rep-mode may expect that CW #0 (or TB#1) is always enabled, and CW #1 (or TB #2) is enabled or disabled.

When CW #1 is disabled, the UE may expect that a PDSCH is transmittedonly through one of TRPs/beams corresponding to two RS sets. An RS setcorresponding to the TRP/beam through which the PDSCH (CW #0 or TB #1)is transmitted may be determined based on DCI fields (e.g., NDI, MCS,and RV) corresponding to CW #1 (or TB #2).

In a specific example, it is assumed that the BS indicates/configuresTCI state={RS set #0, RS set #1} to/for the UE, and CW #1 is disabled.When the NDI field corresponding to CW #1 has a value of 0, CW #0 may betransmitted through a beam indicated by RS set #0. Then, the UE may notexpect that a DL signal may be transmitted in RS set #1 in the abovecase.

2.1.4. Method for Configuring Association Between RV Fields for Two CWs

2.1.4.1. First Method for Configuring Association Between RV Fields forTwo CWs

The UE configured with the PDSCH-rep-mode may determine the RV value ofCW #1 based on (i) the RV of CW #0 and/or a higher-layer configuration(e.g., RRC or a MAC-CE). RV values available for CW #0 and CW #1 may beconfigured to satisfy at least one of the following conditions. Forexample, the RV values that CW #0 and CW #1 may have may be configuredto one of a plurality of combinations to satisfy at least one conditionto be described later. Two combination groups may be configured, andeach combination group may be configured to satisfy Alt #1 and Alt #2.

-   -   Alt #1: Two CWs indicated/allocated by one DCI are mapped to        self-decodable RVs (e.g., RV #0 and RV #3) and        non-self-decodable RVs (e.g. RV #1 and RV #2), respectively. For        example, Alt #1 may correspond to a case in which an RRC        parameter value is 0 in the following embodiment.    -   Alt #2: Two CWs indicated/allocated by one DCI are mapped        commonly to self-decodable RVs (e.g., RV #0 and RV #3) or        non-self-decodable RVs (e.g. RV #1 and RV #2). For example, Alt        #2 may correspond to a case in which the RRC parameter value is        1 in the following embodiment.

One combination group may include both a specific RV combination and anRV combination in a completely exclusive relationship with the specificRV combination. For example, the specific combination group may includeboth of {CW #0 with RV #0, CW #1 with RV #2} and {CW #0 with RV #3, CW#1 with RV #1}.

One combination group may include both a specific combination and acombination symmetrical to the specific combination. For example, thespecific combination group may include both of {CW #0 with RV #0, CW #1with RV #2} and {CW #0 with RV #2, CW #1 with RV #0}.

As described above, CW #1 may be generated from the same informationsequence as CW #0. Accordingly, the RV value of CW #1 may be determinedbased on the RV value of CW #0.

When two CWs are configured for a specific UE, DCI fields provided tothe UE by the BS may include DCI fields for two TBs (e.g., TB #1 and TB#2) as illustrated in the following table. When the two CWs aregenerated from the same information sequence, an NDI field for a secondCW (or TB #2) may be unnecessary. Further, when the RV of the second CW(or TB #2) is determined based on the RV of a first CW (or TB #1) asdescribed above, the RV field for the second CW (or TB #2) may beunnecessary.

TABLE 24 For transport block 1: Modulation and coding scheme - 5 bitsNew data indicator - 1 bit Redundancy version - 2 bits For transportblock 2 (only present if maxNrofCodeWordsScheduledByDCI equals 2):Modulation and coding scheme - 5 bits New data indicator - 1 bitRedundancy version - 2 bits

In this case, according to the present disclosure, the BS and the UE mayoperate according to various embodiments as follows. Various embodimentsof the BS and the UE may be implemented based on Table 25 below.

TABLE 25 RRC parameter {CW#0, CW#1} {CW#0, CW#1} {CW#0, CW#1} {CW#0,CW#1} 0 {RV#0, RV#2} {RV#3, RV#1} {RV#2, RV#0} {RV#1, RV#3} 1 {RV#0,RV#3} {RV#2, RV#1} {RV#3, RV#0} {RV#1, RV#2}

For example, when the RRC parameter value is 0 and the RV value of CW #0is 0 in Table 23, the RV value of CW #1 may be determined to be 2. Assuch, RV #0 and RV #2 generally have a low correlation between the twoCWs, and thus, the receiver may obtain a larger coding gain.

Subsequently, when the RV value of CW #0 is set to 3 for retransmissionof a specific signal, the RV value of CW #1 may be determined to be 1.In this case, the UE may receive all of RVs #0, #1, #2, and #3corresponding to a specific information sequence from the BS in oneretransmission. Accordingly, the receiver of the UE may obtain thelargest coding gain.

In another example, it may be noted from Table 25 that the fourth columnis symmetrical to the second column. For a detailed description, it isassumed that when the RRC parameter value is set to 0, the UEsuccessfully receives CW #1 with RV #2, but fails to receive CW #0 withRV #0. In this case, since most of systematic codes are missing, thereis a high possibility that the UE fails to decode the received signal.

However, when the corresponding signal is retransmitted and CW #1 withRV #0 is indicated for the retransmission, a signal corresponding to RV#0 may be received from a different TRP from the previous TRP. As far asblockage does not occur simultaneously between the two TRPs and the UEwithin a predetermined time, reception of a self-decodable CW may beguaranteed with one retransmission.

As a result, spatial/beam diversity may be provided for a self-decodablecode. In addition, even when the RRC parameter value is set to 1,spatial/beam diversity may be provided for the same self-decodable code(e.g., {CW #0 with RV #0, CW #1 with RV #3} & {CW #0 with RV #3, CW #1with RV #0})

In another example, when the RRC parameter value is 1 and the RV valueof CW #0 is 0 in Table 25, the RV value of CW #1 may be determined to be3. Since RV #0 and RV #3 almost share a systematic code technically,performance may decrease in terms of a coding gain. However, even thoughthe UE receives only one CW, the CW may be self-decodable. Therefore, ifblockage does not occur between the two TRPs and the UE, the UE mayalways receive a self-decodable CW.

When a specific signal is retransmitted and the RV value of CW #0 is setto 2 for the retransmission, the RV value of CW #1 may be determined tobe 1. Thus, the UE may obtain all of RVs #0, #1, #2, and #3 of thespecific signal (or information sequence) with one retransmission, andthus may obtain the largest coding gain.

According to the above-described method, the BS does not need toseparately define the RV bit (or field) of CW #1 in DCI. As a result,the BS may reduce the size of bits signaled in the DCI or use thecorresponding bit field for other purposes.

Additionally, compared to the above-described example, the BS mayindicate/configure one of the rows of the following table by an RRCparameter and/or a DCI field. For example, when the BSindicates/configures, to/for the UE, one of the rows of the followingtable by the DCI field, the BS may indicate/configure one row (e.g., 0or 1 may be indicated/configured) by one or more of an NDI field for asecond TB defined in the DCI and/or an RV field for the second TB and/oran MCS field for the second TB.

Further, as in the above-described example, the RV value of CW #1 may bedetermined based on the RRC parameter and the RV value of CW #0, or apairing index may be indicated/configured based on DCI and/or RRC asillustrated in Table 26 below. In the present disclosure, a pairingindex may refer to an index indicating a configuration in which {RVvalue for CW #0, RV value for CW #1} are paired with each other.

In the following table, 2 bits in DCI and 1 bit in RRC signaling may berequired. For example, for 2-bit information in DCI, the RV field for CW#0 (or CW #1) may be used.

TABLE 26 DCI field RRC 00 01 10 11 parameter {CW#0, CW#1} {CW#0. CW#1}{CW#0, CW#1} {CW#0, CW#1} 0 {RV#0, RV#2} {RV#3, RV#1} {RV#2, RV#0}{RV#1, RV#3} 1 {RV#0, RV#3} {RV#2, RV#1} {RV#3, RV#0} {RV#1, RV#2}

2.1.4.2. Second Method for Configuring Association Between RV Fields ofTwo CWs

The UE configured with the PDSCH-rep-mode may not expect that the RVfield (or RV value) of CW #1 (or TB #2) is indicated/configured. Inother words, for the UE configured with the PDSCH-rep-mode, the BS maynot separately indicate/configure the RV field (or RV value) of CW #1(or TB #2). However, the UE may expect that the starting point of CW #1corresponds to a point immediately after the ending point of CW #0.

The PDSCH-rep-mode may be interpreted as two CWs beingconfigured/indicated from the perspective of signaling. However, the twoCWs are generated substantially from the same information sequence, andthe PDSCH-rep-mode may be interpreted as one CW beingconfigured/indicated under circumstances. For example, since two CWs aregenerated from the same information sequence, when CW #0 is aself-decodable CW (e.g., RV #0 or RV #3), even when CW #1 simplyincludes only redundant bits, the CWs are decodable from the viewpointof the UE. In this case, when CW #1 includes coded bits startingimmediately after the end of CW #0, the UE may maximize a coding gain.In this case, since the BS does not need to separately define an RV forCW #1, signaling overhead may be reduced.

FIG. 10 is a simplified diagram illustrating an example of operations ofa UE and a BS (e.g., an entity including TRP #1 and TRP #2) applicableto the present disclosure.

First, the UE may be configured with the PDSCH-rep-mode by the BS. Asdescribed before in section 2.1.1., the configuration may be performedin one or more of the following methods.

-   -   1) The PDSCH-rep-mode is configured by higher-layer signaling        (e.g., RRC signaling and/or a MAC-CE) from the BS.    -   2) When (i) DCI including a CRC scrambled with an RNTI for the        PDSCH-rep-mode is indicated to the UE and/or (ii) the BS        indicates a TCI state including two RS sets (or two TCI states)        to the UE by the DCI and/or (iii) the PDSCH-rep-mode is        configured for the UE by higher-layer signaling, the        PDSCH-rep-mode is configured.

In other words, when the PDSCH-rep-mode is configured based on 1) in theabove-described methods, the UE may additionally receive a PDCCH thatschedules PDSCH #1 and/or PDSCH #2 from TRP #1 or TRP #2.

Alternatively, when the PDSCH-rep-mode is configured based on 2) amongthe afore-described methods, the UE may be configured with thePDSCH-rep-mode based on determination that (i) DCI included in a PDCCHthat schedules PDSCH #1 and/or PDSCH #2 received from TRP #1 or TRP #2includes a CRC scrambled with the RNTI for the PDSCH-rep-mode, and/or(ii) the DCI indicates a TCI state including two RS sets (or two TCIstates).

In addition, based on at least one of the above-described methods insections 2.1.2 to 2.1.4, the UE may receive PDSCH #1 (or CW #0 or TB #1)and/or PDSCH #2 (or CW #1 or TB #2) from TRP #1 and/or TRP #2.

For a more specific method, the methods described in sections 2.1.2 to2.1.4 may be applied.

In the present disclosure, the operation of transmitting CWs generatedfrom the same information sequence to a UE by two different TRPs maycorresponds to an operation for an ultra-reliable low latencycommunication (URLLC) system. In other words, for the URLLC service, theBS may transmit TBs (CWs or PDSCHs) having the same information to oneUE through different TRPs. On the contrary, the operation oftransmitting CWs generated from different information sequences to a UEby two different TRPs may corresponds to an operation for an enhancedmobile broadband (eMBB) system.

Based on the above description, the BS may signal to the UE whether theURLLC service (signals transmitted from two TRPs have the sameinformation) or the eMBB service (signals transmitted from two TRPs havedifferent information) is supported. A specific method for the signalingmay be performed using RRC signaling, an RNTI, and so on.

When the BS supports the URLLC service, TB fields in DCI transmitted forscheduling by the BS may provide TB information (e.g., an MCS, a coderate, an RV, and so on) for a signal transmitted from each TRP, as isdone conventionally.

When the BS supports the URLLC service, the UE may interpret fields fortwo TBs in the DCI according to various methods of the presentdisclosure. For example, the UE may obtain only code rate informationfrom some bit information of fields for a second TB.

Further, as described before, RV information about each signal may beexplicitly signaled as in the examples of the present disclosure ordetermined based on an implicit rule.

In the present disclosure, schemes for multi-TRP-based URLLC, scheduledby a single DCI may include the following schemes.

(1) Scheme 1 (SDM)

n (n<=N_(s)) TCI states in a single slot may be configured along withoverlapped time and frequency resource allocations.

(1-1) Scheme 1a

-   -   Each transmission occasion may be a layer or a set of layers of        the same TB, with each layer or layer set associated with one        TCI and one set of DMRS port(s).

A single codeword with one RV may be used across all spatial layers orlayer sets. From the perspective of the UE, different coded bits may bemapped to different layers or layer sets with the same mapping rule.

(1-2) Scheme 1b

-   -   Each transmission occasion may be a layer or a set of layers of        the same TB, with each layer or layer set associated with one        TCI and one set of DMRS port(s).    -   A single codeword with one RV may be used for each spatial layer        or layer set. The RVs corresponding to each spatial layer or        layer set may be the same or different.    -   When the total number of layers is equal to or less than 4,        codeword-to-layer mapping may be applied.

(1-3) Scheme 1c

-   -   One transmission occasion may be (i) one layer of the same TB        with one DMRS port associated with multiple TCI state indices,        or (ii) one layer of the same TB with multiple DMRS ports        associated with multiple TCI state indices one to one.

For scheme 1, applying different MCSs/modulation orders for differentlayers or layer sets may be considered.

(2) Scheme 2 (FDM)

n (n<=N_(f)) TCI states in a single slot may be configured along withnon-overlapped frequency resource allocations.

For scheme 2, each non-overlapped frequency resource allocation may beassociated with one TCI state.

For scheme 2, the same single/multiple DMRS port(s) may be associatedwith all non-overlapped frequency resource allocations.

(2-1) Scheme 2a

A single codeword with one RV may be used across full resourceallocations. From the perspective of the UE, common RB mapping(codeword-to-layer mapping) may be applied across full resourceallocations.

(2-2) Scheme 2b

A single codeword with one RV may be used for each non-overlappedfrequency resource allocation. The RVs corresponding to thenon-overlapped frequency resource allocations may be the same ordifferent.

For scheme 2, applying different MCSs/modulation orders for differentnon-overlapped frequency resource allocations may be considered.

For example, for RV sequences applied to RBs sequentially associatedwith two TCI states, RV_(id) indicated by DCI may be used to select oneof four RV sequence candidates in single DCI-based multi-TRP (e.g.,M-TRP) URLLC.

In another example, in single DCI-based multi-TRP (e.g., M-TRP) URLLC,the following RV sequence candidates may be supported: (0, 2), (2, 3),(3, 1), and (1, 0).

(3) Scheme 3 (TDM)

n (n<=N_(t1)) TCI states in a single slot may be configured along withnon-overlapped time resource allocations.

For scheme 3, each transmission occasion of a TB may have one TCI andone RV with a time granularity of a mini-slot.

For scheme 3, all transmission occasion(s) within the slot may use acommon MCS with the same single/multiple DMRS port(s).

For example, for RV sequences applied to RBs sequentially associatedwith two TCI states, RVi_(d) indicated by DCI may be used to select oneof four RV sequence candidates in single DCI-based multi-TRP (e.g.,M-TRP) URLLC.

In another example, in single DCI-based multi-TRP (e.g., M-TRP) URLLC,the following RV sequence candidates may be supported: (0, 2), (2, 3),(3, 1), and (1, 0).

The RV/TCI state may be the same or different among transmissionoccasions.

For scheme 3, channel estimation interpolation may be applied acrossmini-slots with the same TCI index.

(4) Scheme 4 (TDM)

n (n<=N_(t2)) TCI states may be configured in K (n<=K) different slots.

For scheme 4, each transmission occasion of a TB may have one TCI andone RV.

For scheme 4, all transmission occasion(s) across K slots may use acommon MCS with the same single/multiple DMRS port(s).

The RV/TCI state may be the same or different among transmissionoccasions.

For scheme 4, channel estimation interpolation may be applied acrossslots with the same TCI index.

In the present disclosure, M-TRP/panel-based URLLC schemes may becompared in terms of (i) improved reliability, (ii) efficiency, and(iii) specification impact.

Support of the number of layers per TRP may be discussed later.

In the present disclosure, N_(s), N_(f), N_(t1), and N_(t2) are valuesset by the BS. These values may be determined/set by higher-layersignaling and/or DCI.

Based on the above disclosure, the multi-TRP-based URLLC, scheduled by asingle DCI may support the following.

For example, the multi-TRP based URLLC, scheduled by single DCI maysupport an operation based on scheme 1a.

In another example, the multi-TRP-based URLLC scheduled by single DCImay support at least one of scheme 2a or scheme 2b. For this purpose,system level simulator (SLS) and link level simulator (LLS) simulationresults may be considered.

FIG. 11 is a simplified diagram illustrating operations of a UE and a BSaccording to an example of the present disclosure, FIG. 12 is aflowchart illustrating a UE operation according to an example of thepresent disclosure, and FIG. 13 is a flowchart illustrating a BSoperation according to an example of the present disclosure.

The UE may receive DCI including a plurality of TCI states from the BS(S1110 and S1210). The BS may transmit the DCI to the UE (S1110 andS1310).

In the present disclosure, the DCI may include information about two TBscorresponding to two CWs, respectively. For example, the DCI may includeinformation described in Table 22.

In the present disclosure, each of the plurality of TCI states may beassociated with one RS set.

The UE may obtain, from the BS, mode information related to a first modein which a plurality of data based on the same information aretransmitted.

In an example applicable to the present disclosure, the first mode mayinclude a multi-TRP-based URLLC mode. In another example, the modeinformation may be related to the first mode or a second mode includinga multi-TRP-based eMBB mode.

In an example applicable to the present disclosure, the UE may receivethe mode information by higher-layer signaling including RRC signaling(S1120 and S1220). The BS may transmit the mode information to the UE bythe higher-layer signaling (S1120 and S1320). Transmission and receptionof the mode information may precede or follow transmission and receptionof the DCI in the time domain.

Alternatively, in another example applicable to the present disclosure,the UE may obtain the mode information based on DCI including a CRCscrambled with an RNTI related to the first mode. In other words, the UEmay obtain the mode information related to the first mode withoutadditional scheduling.

The UE may assume based on the DCI and the mode information that (i)data reception is scheduled by at least one of a plurality of TRPsrelated to the DCI, and (ii) data received from the plurality of TRPsare based on the same information (S1130 and S1230).

Subsequently, the UE may obtain data information from at least one ofthe plurality of TRPs based on the assumption (S1140 and S1240). The BSmay transmit the data information through the at least one of theplurality of TRPs in the DCI, based on the DCI and the mode information(S1140 and S1330).

In a specific example, the UE may obtain the data information in eachPDSCH occasion related to two TRPs among the plurality of TRPs based on(i) DCI indicating enable of two CWs and (ii) the assumption. In thepresent disclosure, a PDSCH occasion may mean a PDSCH (or PDSCHcandidate) associated with the same information (e.g., the same TB)related to a plurality of TCI states (e.g., two TCI states).

For example, RV information for the two PDSCH occasions may bedetermined based on one of (i) an RV combination for the two PDSCHoccasions being determined based on RV information related to a firstCW, included in the DCI or (ii) RV information related to a secondcodeword being determined based on the RV information related to thefirst CW in the RV information for the two PDSCH occasions.

In another example, the RV information for the two PDSCH occasions maybe configured/indicated as one of {RV #0, RV #2}, {RV #1, RV #3}, {RV#2, RV #0}, and {RV #3, RV #1}.

In another specific example, the UE may obtain the data information in aPDSCH occasion related to one of the plurality of TRPs based on (i) theDCI indicating enable of one of two codewords and the assumption.

The PDSCH occasion may be associated with one TCI state determined basedon the DCI among the plurality of TCI states.

2.2. Single PDCCH Based Signaling and UE Behaviors for PDSCH Repetition

2.2.1. Method for Determination of TB Size from Two CWs

2.2.1.1. First TBS Determination Method

A UE configured with the PDSCH-rep-mode may determine the TB size basedon at least one of the MCS of a CW having a self-decodable RV (e.g., RV#0, RV #3), resource allocation, or the number of layers.

In this case, when the RVs of two CWs are the same, the UE may determinethe TB size based on at least one of the MCS of CW #0 (or CW #1), thenumber of available REs, or the number of layers.

Alternatively, when the RVs of the two CWs are RV #0 and RV #3, the UEmay determine the TB size based on at least one of the MCS of the CWhaving RV #0 (or RV #3), the number of available REs, or the number oflayers.

In this case, a more specific TBS determination method may be based onthe above-described TBS determination method. In addition, the UE maycalculate the number of available REs based on the resources allocatedto the UE. The UE may determine the number of layers based on the numberof DMRS ports having an association with the corresponding CW.

In the present disclosure, two CWs may differ from each other in termsof at least one of the MCS, the number of layers, or the number ofavailable REs. In this case, the TB size corresponding may be determineddifferently according to each CW. However, according to thePDSCH-rep-mode described in the present disclosure, the two CWs aregenerated based on the same TB, and accordingly it may be unclear the CWforming the basis of determination of the TB size by the UE.

To address this issue, when one of the two CWs has a self-decodable RVvalue, the UE should be allowed to perform decoding with only the CW.Accordingly, in selecting a CW for determining the TB size, the UEaccording to the present disclosure may preferentially select aself-decodable RV value. In addition, since RV #0 generally exhibitsbetter performance than RV #3, the UE may select RV #0 in preference toRV #3.

2.2.1.2. Second TBS Determination Method

A UE configured with the PDSCH-rep-mode may determine the TB size basedon at least one of the MCS of CW #0 (or CW #1), resource allocation, orthe number of layers.

According to this exemplary operation, the UE may select a TB related toa specific CW without separate signaling. Accordingly, signalingoverhead may be reduced, and overall system complexity may be lowered.

However, when (i) CW #0 and CW #1 correspond to RS set #0 and RS set #1of the TCI state, respectively, and (ii) the TB size is determined basedon CW #0, the UE may determine the TB size based on the beam indicatedby RS set #0.

However, according to this method, when the state of the beam indicatedby set #1 is better than the state of the beam indicated by RS set #0,loss may occur in terms of throughput because the UE should determinethe TB size based on the state of the beam indicated by RS set #0.

2.2.1.3. Third TBS Determination Method

A UE configured with the PDSCH-rep-mode may determine each TB size basedon at least one of an MCS corresponding to each of the indicated twoCWs, resource allocation, and the number of layers. Subsequently, the UEmay select a larger one of the calculated TB sizes corresponding to thetwo CWs as a (representative) TB size.

For example, when the TB size of CW #0 is larger than the TB size of CW#1, the UE may select the TB size of CW #0. This example may beadvantageous in terms of throughput as the BS may transmit moreinformation to the UE through one transmission.

2.2.1.4. Fourth TBS Determination Method

A UE configured with the PDSCH-rep-mode may determine the TB sizecorresponding to the CW indicated by DCI and/or higher layer signaling(e.g., RRC or MCA-CE, etc.).

As a specific example, when the NDI for the second TB of the DCI is 0,the UE may select the TB corresponding to CW #0 as a (representative)TB. On the other hand, when the NDI for the second TB of the DCI is 1,the UE may select the TB corresponding to CW #1 as a (representative)TB.

In the example above, the NDI field for the second TB of the DCI may bereplaced with an RV field for the second TB of the DCI or a specificfield of a higher layer parameter.

2.2.1.5. Fifth TBS Determination Method

A UE configured with the PDSCH-rep-mode may determine the TB size basedon CW #0 (or TB #1). In addition, the UE may determine/assume a CW-to-RSset mapping relationship based on the NDI, and/or RV, and/or MCS fieldsof CW #1 (or TB #2). In other words, the BS may indicate/configure theCW-to-RS set mapping relationship to the UE based on the NDI, and/or RV,and/or MCS fields of CW #1 (or TB #2).

In the example above, the remaining bit information in the DCI may bereserved as a specific value. In this case, the reserved specific valuemay be determined/set based on a configuration value for disabling theCW.

Alternatively, in the example above, the UE may determine the TB sizebased on CW1 (or TB #2) rather than CW #0.

Alternatively, the remaining bit information in the DCI may not bedefined separately. Accordingly, the UE may not expect that theremaining bit information in the DCI is configured. In this case, the BSmay save bits in the DCI.

When two CWs are scheduled by a single PDCCH (e.g., Single PDCCH with2CW), the BS may configure only one frequency domain resource assignment(FRA) to the UE. At this time, when the FRA bit field is divided intotwo parts to indicate the frequency positions of CW #0 and CW #1, the UEmay assume that the most significant bit (MSB) of the FRA and the leastsignificant bit (LSB) of the FRA indicates/allocates the frequencypositions of CW #0 and CW #1, respectively.

As a specific example, the UE may determine the TB size based on CW #0.In this case, the LSB (3 bits) and RV (2 bits) fields of the MCS for CW#1 (or TB #2) excluding the NDI field for CW #1 (or TB #2) may be set to0 (the MSB (2 bits) of the MCS may be used to indicate the modulationorder of CW #1). In this case, the 3 bits of the LSB and the 2 bits ofthe RV of the MCS are known bits, and accordingly the UE may improvedecoding performance of the PDCCH using the same. When the NDI for CW #1(or TB #2) is equal to 0, the UE may expect that CW #0/#1 are mapped toRS set #0/#1, respectively. On the other hand, when the NDI for CW #1(or TB #2) is equal to 1, the UE may expect that CW #0/#1 are mapped toRS set #1/#0, respectively.

As another specific example, in determining the LSB and RV bits of theMCS, the UE may consider a disable option of the CW (e.g., even when theTCI state is configured with two RS sets, only specific one RS set isset to be valid, using a CW disable option). For example, MCS=26 (11010)and RV=1 (01) may be set as signaling values for the CW disable option.In consideration of the binary values, ‘010’ and ‘01’ may be set as thedefault values of the LSB and RV of the MCS. When the demodulation orderof CW #1 is indicated/set by LSB 2 bits of MCS, the MSB 3 bits and RV 2bits of MCS may be determined as/set to ‘110’ and ‘01’, respectively.

As another specific example, in the above-described example, the RVfield may indicate the modulation order of CW #1 instead of the MCSfield. In this case, all 5 bits of the MCS field may be reserved as‘11010’. However, when RV=′01′ and MCS=′11010′, CW #1 may be disabled,and therefore a value other than ‘11010’ may be set as a default valueof the MCS field. However, in order to indicate disabling of CW #1, theMCS field may have a value of ‘11010’.

According to the above-described method, since the UE may determine thepositions of known bits (e.g., 5 bits) before decoding the signal, itmay use the known bits in decoding the signal. In addition, the BS maydynamically switch the CW-to-RS set relationship through NDI.

Accordingly, flexibility allowing a TB to be selected according to thebeam state may be provided.

However, in order to improve the PDCCH decoding performance of the UEaccording to the above-described method, the UE should assume that thePDSCH-rep-mode is configured before decoding the PDCCH. If the UE needsto determine whether or not the PDSCH-rep-mode is configured through theTCI state and MCS-C-RNTI check, the UE should perform decoding of thePDCCH based on two hypotheses including the case where thePDSCH-rep-mode is configured and the case where the PDSCH-rep-mode isnot configured. Accordingly, in this case, obtaining performanceimprovement may require cause increase in the complexity of PDCCHdecoding of the UE.

2.2.2. Signaling Methods Using MCS of CW which is not Related toSelected TB (or CW #1)

2.2.2.1. First Signaling Method Using MCS

A UE configured with the PDSCH-rep-mode may determine the modulationorder of a CW not used for TBS determination based on some bits (e.g.,MSB, LSB) of the MCS field and/or the RV field for the CW (not used forTBS determination). In this case, the remaining bit information in theMCS field may be fixed to a specific value (e.g., reserve).

When the TB size is determined based on at least one of the MCS, RV, andresource allocation for CW #0 for the UE for which the PDSCH-rep-mode isconfigured, a code-rate other than the demodulation order may not beneeded in the MCS field for CW #1 (TB #2) in the DCI transmitted fromthe BS to the UE. In other words, in this case, the BS mayindicate/configure only the modulation order to the UE using only somebits of the MCS field (e.g., 5 bits) in the DCI.

In Table 27 below, it is assumed that the MCS field has a size of 5bits, and that a part marked “XXX” may be set to any bits. This isbecause the part marked “XXX” does not affect the modulation order. Assuch, based on Table 27 below, the UE may determine the modulation orderbased only on the MSB of the MCS field of the CW that is not used in TBSdetermination.

TABLE 27 MCS field Modulation Order 00XXX QPSK 01XXX 16QAM 10XXX 64QAM11XXX 256QAM

Here, when the part marked “XXX” is fixed to a specific value (e.g.,“000”), the UE may perform PDCCH decoding by processing this value as aknown bit in PDCCH decoding. As a result, the UE may improve the PDCCHdecoding performance.

Alternatively, the part marked “XXX” may not be defined separately.Thereby, the BS may minimize the bit information in the DCI (bitsaving). Alternatively, the BS may use the bit information for a purposedifferent from the conventional one.

2.2.2.2. Second Signaling Method Using MCS

A UE configured with the PDSCH-rep-mode may determine the modulationorder of CW #1 based on the NDI for TB #2, and/or some bits (e.g., MSB,LSB) of the MCS for TB #2, and/or the RV field for TB #2. In this case,the remaining bits of the MCS field may be fixed to a specific value orreserved.

According to this method, the UE may determine the modulation order ofCW #1 based on the DCI field corresponding to TB #2. The BS may fix theremaining bit information (e.g., unused bit information in the MCSfield) to a specific value. Accordingly, the UE may operate more simply.

In a specific example, the MCS field corresponding to TB #2 may beredefined as shown in the table below. In this case, the UE maydetermine the modulation order of CW #1 based on the MSB 2 bits of theMCS field.

TABLE 28 MCS field of TB#2 Modulation Order 00XXX QPSK 01XXX 16QAM 10XXX64QAM 11XXX 256QAM

Alternatively, the UE may determine the modulation order of CW #1 basedon the RV for TB #2 in the DCI based on Table 29 below.

TABLE 29 RV field of TB#2 Modulation Order 00 QPSK 01 16QAM 10 64QAM 11256QAM

2.2.3. ACK/NACK Feedback

2.2.3.1. First ACK/NACK Feedback

When two enabled CWs are indicated/configured by a BS to a UE configuredwith the PDSCH-rep-mode, the UE may feed back only a single ACK/NACK tothe BS.

As described above, CW #0 and CW #1 may be generated from the sameinformation sequence (or from the same TB). Accordingly, even when twoCWs are indicated/configured to the UE, the UE may feed back only asingle ACK/NACK. Alternatively, in the case above, the BS may defineonly one ACK/NACK for the UE.

2.2.3.2. Second ACK/NACK Feedback

The UE receiving the PDSCH through the PDSCH-rep-mode may determinewhether to re-receive the PDSCH, based on the HARQ process number and/orthe NDI field related to CW #0 (or CW #1).

Specifically, the UE receiving the PDSCH through the PDSCH-rep-mode mayreceive one TB through the 2CW-based DCI. In this case, the size of theTB may be determined based on CW #0. Accordingly, when retransmission isperformed, the BS may not toggle the NDI field related to CW #0, butindicate the same value as before, and informs the UE of the HARQprocess number, thereby configuring, to the UE, whether to retransmit aspecific PDSCH.

FIG. 14 is a diagram schematically illustrating an exemplary operationof a UE and a BS (e.g., an object including TRP #1 and TRP #2)applicable to the present disclosure.

First, the PDSCH-rep-mode may be configured for the UE by the BS. Asdescribed above in section 2.1.1, the configuration may be establishedthrough one or more of the following methods.

-   -   1) Establishing the configuration through higher layer signaling        (e.g., RRC and/or MAC-CE, etc.) of the BS; and    -   2) (i) DCI including CRC scrambled with RNTI for PDSCH-rep-mode        is indicated to the UE, and/or (ii) the BS indicates a TCI state        (or two TCI states) having the DCI including two RS sets to the        UE, and/or (iii) the PDSCH-rep-mode is configured for the UE by        higher layer signaling.

In other words, when the PDSCH-rep-mode is configured based on method 1)between the above-described methods, the UE may additionally receive aPDCCH for scheduling PDSCH #1 and/or PDSCH #2 from TRP #1 or TRP #2.

Alternatively, when the PDSCH-rep-mode is to be configured based onmethod 2) between the above-described methods, the PDSCH-rep-mode may beconfigured for the UE based on the determination that (i) the DCIincluded in a PDCCH for scheduling PDSCH #1 and/or PDSCH #2 receivedfrom TRP #1 or TRP #2 includes a CRC scrambled with an RNTI for thePDSCH-rep-mode, and/or (ii) a TCI state (or two TCI states) includingtwo RS sets is indicated.

In addition, based on at least one of the methods according to sections2.1.2 to 2.1.4 or 2.2.1 to 2.2.3 above, the UE may receive PDSCH #1 (orCW #0 or TB #1) and/or PDSCH #2 (or CW #1 or TB #2) transmitted from TRP#1 and/or TRP #2.

Unlike the example of FIG. 14, the technical configuration according tothe present disclosure may be applied even to a configuration in whichthe UE receives PDSCH #1 and PDSCH #2 from the BS (without distinctionbetween TRPs). In other words, the features may be applied to (i) anoperation of the UE of receiving the respective PDSCHs (e.g., PDSCH #1and PDSCH #2) through different TRPs, or (ii) an operation of the UE ofreceiving the respective PDSCHs (e.g., PDSCH #1 and PDSCH #2) throughthe same TRP.

In this case, PDSCH #1 (or CW #0 or TB #1) may be related to a first TCIstate among a plurality of TCI states, and PDSCH #2 (or CW #1 or TB #2)may be related to a second TCI state among the plurality of TCI states.

Accordingly, as an example applicable to the present disclosure, RBsallocated to the PDSCH associated with the first TCI state in the TCIcode point may be used for TBS determination with single MCS indication,while same TBS and modulation order can be assumed for the RBs allocatedto PDSCH related to the second TCI state.

As another example, the UE may determine a TB size related to two CWsscheduled by a single PDCCH, based on various methods disclosed insection 2.2.1. In addition, the UE may determine the modulation orderfor a CW not related to the TB size determination described above, basedon the various methods disclosed in section 2.2.2. Accordingly, the UEmay receive the two CWs based on the determined TB size and modulationorder.

In addition, the UE may receive ACK/NACK feedback related to the two CWsscheduled by a single PDCCH based on various methods disclosed insection 2.2.3 and receive a retransmitted signal based thereon.

As more specific methods, the methods disclosed in sections 2.1.2 to2.1.4, and 2.2 above may be applied.

FIG. 15 is a diagram schematically illustrating the operation of a UEand a BS according to an example of the present disclosure, FIG. 16 is aflowchart of an operation of the UE according to an example of thepresent disclosure, and FIG. 17 is a flowchart of an operation of the BSaccording to an example of the present disclosure.

The UE may receive, from the BS, DCI including (i) a plurality of TCIstates and (ii) information for two TBs (S1510, S1610). In acorresponding operation, the BS may transmit the DCI to the UE (S1510,S1710).

In the present disclosure, each of the plurality of TCI states may berelated to one RS set.

The UE may obtain, from the BS, mode information related to a first modein which a plurality of data based on the same information istransmitted.

As an example applicable to the present disclosure, the first mode mayinclude a multi-TRP-based URLLLC (ultra-reliable low latencycommunication) mode. As another example, the mode information may berelated to one of the first mode or a second mode including amulti-TRP-based eMBB (enhanced mobile broadband) mode.

As an example applicable to the present disclosure, the UE may receivethe mode information through higher layer signaling including RRCsignaling (S1520, S1620). In a corresponding operation, the BS maytransmit the mode information to the UE through higher layer signaling(S1520, S1720). In this case, the transmission and reception of the modeinformation may be performed before or after the transmission andreception of the above-described DCI in the time domain.

Alternatively, as another example applicable to the present disclosure,the UE may obtain the information based on DCI including a cyclicredundancy check (CRC) scrambled with a radio network temporaryidentifier (RNTI) related to the first mode. In other words, the UE mayobtain the mode information related to the first mode without additionalsignaling.

Based on the DCI and the mode information, the UE may assume that (i)data reception is scheduled from a plurality of TRPs by the DCI, and(ii) data received from the plurality of TRPs is based on the sameinformation (S1530, S1630).

Subsequently, based on the assumption, the UE may determine a transportblock size (TBS) related to the data based on information related to oneof the two TBs related to the DCI (S1540 and S1640).

As an example applicable to the present disclosure, the informationrelated to the one TB may be information related to a TB related to acodeword having self-decodable redundancy version (RV) informationbetween the two codewords related to the DCI.

Here, the self-decodable RV information may include information relatedto RV index 0 or RV index 3.

As another example applicable to the present disclosure, the informationrelated to the one TB may be information related to a codeword having afirst codeword index between the two codewords related to the DCI.

As another example applicable to the present disclosure, the informationrelated to the one TB may be information related to a PDSCH related to afirst TCI state among a plurality of TCI states related to the DCI.

As another example applicable to the present disclosure, the informationrelated to the one TB may be information related to a codeword having alarge TBS related to the two codewords related to the DCI.

As another example applicable to the present disclosure, the informationrelated to the one TB may be information related to one codewordindicated by the BS between the two codewords related to the DCI.

Here, the one codeword indicated by the BS may be determined based onnew data indicator (NDI) information related to a second TB in theinformation for the two TBs in the DCI.

In the present disclosure, a modulation order of the one TB may bedetermined based on the information related to the one TB, and themodulation order of the other one of the two TBs may be determined basedon the information related to the other one of the TBs.

Here, the information related to the other TB may include at least oneof the followings:

-   -   At least one bit information of NDI information related to the        other TB;    -   At least one bit information of MCS (modulation and coding        scheme) information related to the other TB; and    -   RV information related to the other TB.

Subsequently, the UE may obtain data information from the plurality ofTRPs based on the TBS (S1550, S1650).

In a corresponding operation, the BS may transmit the data informationto the UE through a plurality of TRPs based on the DCI and the modeinformation (S1550, S1730). In this case, the TBS related to the datainformation may be related to information related to one of the two TBsrelated to the DCI.

In the present disclosure, the UE may additionally transmit oneacknowledgment to the BS in response to the data information obtainedfrom the plurality of TRPs.

2.3. Configuration of Resource Allocation and DMRS Port Indication UsingDCI Fields of the Second TB for CoMP

2.3.1. Method for Dynamically or Statically Indicating Localized PRGs orInterleaved PRGs

2.3.1.1. First PRG Indication Method

A UE configured with the PDSCH-rep-mode may expect that Y PRG modes(where Y is a value of 1 to 4) are preconfigured among a plurality ofPRG modes via from higher layer signaling (e.g., RRC, MAC-CE, etc.).Here, the plurality of PRG modes may include the following modes:overlapped PRGs, localized PRGs, interleaved PRGs, or TDMed PRGs.

In addition, the UE configured with the PDSCH-rep-mode may expect thatone of the Y PRG modes is indicated based on at least one of the newdata indicator (NDI) field for the second TB, and/or the redundancyversion (RV) field for the second TB, and/or the MCS field for thesecond TB. However, when one PRG mode is configured/determined by higherlayer signaling, the DCI fields may not be used for this purpose.

Here, the PRG modes may be defined based on FIG. 7.

In another embodiment, Y PRG modes may be defined according to astandard specification without higher layer signaling. For example, whenonly the localized PRG mode (localized PRGs) or the interleaved PRG mode(interleaved PRGs) is supported, the UE may expect that one of the twoPRG modes is indicated based on at least one of the NDI field for thesecond TB, and/or the RV field for the second TB, and/or MCS field forthe second TB, without higher layer signaling.

2.3.1.2. Second PRG Indication Method

A UE configured with the PDSCH-rep-mode may expect localized PRGs basedon higher layer signaling related to PRB bundling for wideband. As aspecific example, when PRB bundling is configured as a wideband PRB forthe UE through higher layer parameters (e.g., prb-BundlingType,dynamicBundling, etc.), the UE may expect localized PRGs.

Table 30 below shows higher layer parameters related to the PRBbundling.

TABLE 30  prb-BundlingType  CHOICE {   staticBundling   SEQUENCE {bundleSize    ENUMERATED { n4, wideband } OPTIONAL -- Need S   },  dynamicBundling  SEQUENCE { bundleSizeSet1   ENUMERATED { n4,wideband, n2-wideband, n4- wideband }  OPTIONAL, -- Need SbundleSizeSet2   ENUMERATED { n4, wideband } OPTIONAL -- Need S   }  },

In the table above, prb-bundlingType may be related to (or may indicate)a PRB bundle type and bundle size(s). When ‘dynamic’ is selected, theactual bundleSizeSet1 or bundleSizeSet2 to be used may be indicatedthrough DCI. Constraints on the bundleSize(Set) setting may be based onthe vrb-ToPRB-Interleaver and rbg-Size settings. When the value ofbundleSize(Set) is absent, the UE may apply the value of n2 (e.g., 2).

Based on the higher layer parameters, the UE may perform an operationbased on the table below.

More specifically, when the UE receives PDSCH scheduled by PDCCH withDCI format 1_1 with CRC scrambled by C-RNTI, MCS-C-RNTI or CS-RNTI, ifthe higher layer parameter prb-BundlingType is set to ‘dynamicBundling’,(i) the higher layer parameters bundleSizeSet1 and bundleSizeSet2 mayconfigure two sets of P_(BWP,i)′ values, wherein (ii) the first set maytake one or more P_(BWP,i)′ values among {2, 4, wideband}, and (iii) thesecond set may take one P_(BWP,i)′ value among {2, 4, wideband}.

If the PRB bundling size indicator signaled in DCI format 1_1 is set to‘0’, the UE may use a P_(BWP,i)′ value from the second set of P_(BWP,i)′values when receiving PDSCH scheduled by the same DCI. If the PRBbundling size indicator signaled in DCI format 1_1 is set to ‘1’ and onevalue is configured for the first set of P_(BWP,i)′ values, the UE mayuse the P_(BWP,i)′ value when receiving PDSCH scheduled by the same DCI.If the PRB bundling size indicator signaled in DCI format 1_1 is set to‘1’ and two values are configured for the first set of P_(BWP,i)′ valuesas ‘n2-wideband’ (corresponding to two P_(BWP,i)′ values of 2 andwideband) or ‘n4-wideband’ (corresponding to two P_(BWP,i)′ values of 4and wideband), the UE may use the value when receiving PDSCH scheduledby the same DCI as follows: (i) if the scheduled PRBs are contiguous andthe size of the scheduled PRBs is larger than N_(BWP,i) ^(size)/2.P_(BWP,i)′ may be the same as the scheduled bandwidth; (ii) otherwise,P_(BWP,i)′ may be set to the remaining configured values of 2 or 4.

When the UE receives PDSCH scheduled by PDCCH with DCI format 1_1 withCRC scrambled by C-RNTI, MCS-C-RNTI or CS-RNTI, if the higher layerparameter prb-BundlingType is set to ‘staticBundling’, the P_(BWP,i)′value may be configured with a single value indicated by the higherlayer parameter bundleSize.

(i) When a UE is configured with nominal RBG size P=2 for a specificbandwidth part (BWP), or (ii) when a UE is configured with aninterleaving unit of 2 for VRB-to-PRB mapping by the higher layerparameter vrb-ToPRB-Interleaver in PDSCH-Config for a specific BWP, theUE may not be expected to be configured with P_(BWP,i)′=4.

TABLE 31 When receiving PDSCH scheduled by PDCCH with DCI format 1_1with CRC scrambled by C-RNTI, MCS-C- RNTI, or CS-RNTI, if the higherlayer parameter prb-BundlingType is set to ‘dynamicBundling’, the higherlayer parameters bundleSizeSet1 and bundleSizeSet2 configure two sets ofP′_(BWP i) values, the first set can take one or two P′_(BWP i) valuesamong {2, 4, wideband}, and the second set can take one P′_(BWP i) valueamong {2, 4, wideband}. If the PRB bundling size indicator signalled inDCI format 1_1 as defined TS 38.212, is set to ‘0’, the UE shall use theP′_(BWP i) value from the second set of values when receiving PDSCHscheduled by the same DCI. is set to ‘1’ and one value is configured forthe first set of P′_(BWP i) values, the UE shall use this P′_(BWP i)value when receiving PDSCH scheduled by the same DCI is set to ‘1’ andtwo values are configured for the first set of P′_(BWP i) values as‘n2-wideband’ (corresponding to two P′_(BWP i) values 2 and wideband) or‘n4-wideband’ (corresponding to two P′_(BWP i) values 4 and wideband),the UE shall use the value when receiving PDSCH scheduled by the sameDCI as follows: If the scheduled PRBs are contiguous and the size of thescheduled PRBs is larger than N_(BWP, i) ^(size)/2, P′_(BWP i) is thesame as the scheduled bandwidth, otherwise P′_(BWP i) is set to theremaining configured value of 2 or 4, respectively. When receiving PDSCHscheduled by PDCCH with DCI format 1_1 with CRC scrambled by C-RNTI,MCS-C- RNTI, or CS-RNTI, if the higher layer parameter prb-BundlingTypeis set to ‘staticBundling’, the P′_(BWP i) value is configured with thesingle value indicated by the higher layer parameter bundleSize. When aUE is configured with nominal RBG size P = 2 for bandwidth part i, orwhen a UE is configured with interleaving unit of 2 for VRB to PRBmapping provided by the higher layer parameter vrb-ToPRB-Interleavergiven by PDSCH-Config for bandwidth part i, the UE. is not expected tobe configured with P′_(BWP i) = 4.

When the PRB bundling is in a wideband, the UE may improve the channelestimation performance. That is, when all the RBs are adjacent, the UEmay improve the channel estimation and lower the related UE complexity.Accordingly, based on the PRB bundling being set to wideband, the UE mayexpect localized PRGs. Alternatively, based on the PRB bundling beingset to 2 or 4 instead of wideband, the UE may expect interleaved PRGs.

2.3.2. Method for Allocating RBs for Localized PRGs or Interleaved PRGsDynamically

2.3.2.1. First RB Allocation Method

A UE configured with the PDSCH-rep-mode may determine the frequencyposition and/or BW at which each CW is transmitted, based on thefrequency domain resource assignment (FRA), and/or the NDI of the secondTB, and/or the RV of the second TB, and/or the MCS field(s) of thesecond TB.

In the following disclosure, unless otherwise stated, it may be assumedfor simplicity that the size of the PRG and the size of the RBG are thesame. Alternatively, depending on the application example, theoperations described below may be applied even in the case where thesize of the PRG is different from the size of the RBG.

In a first example, it is assumed that the BS allocates 16 RBGs to theUE through the FRA. In this case, it is assumed that both the RBG andPRG sizes are 4.

In this case, when “localized PRGs” are indicated/configured to the UEby the BS, the two CWs may be transmitted on the upper 8 RBGs and thelower 8 RBGs on a frequency basis, respectively. In this case, the UEmay determine whether CW #0 is transmitted on the upper 8 RBGs or thelower 8 RBGs, based on the NDI, and/or RV, and/or MCS of the second TB.CW #1 may be transmitted on other RBGs on which CW #0 is nottransmitted.

FIG. 18 is a diagram illustrating an example of a PRG for each codewordaccording to the present disclosure.

The left part (localized PRGs) of FIG. 18 shows the positions of RBGsincluded in the localized PRG through which CW #0/#1 is transmittedaccording to the values of NDI. The right part (interleaved PRGs) ofFIG. 18 shows the positions of RBGs included in the interleaved PRGthrough which CW #0/#1 is transmitted according to the values of NDI.

As shown in FIG. 18, as a resource unit in which CW is interleaved (oralternated), not only the PRG but also the RBG may be applied. As aspecific example, when RBG is applied as the resource unit, and the RBGand PRG sizes are 4 and 2, respectively, the interleaved RB unit may be4 RBs. For reference, FIG. 18 shows a structure in which RBG-wise orPRG-wise interleaving is performed.

In a second example, it is assumed that the BS allocates 17 RBGs to theUE through the FRA.

In this case, it is difficult to divide the 17 RBGs into exactly twogroups. Accordingly, a specific CW may be transmitted/received through aresource having one more RBG than the other CW.

In this case, a resource having one more RBG may be allocated to a CWhaving a higher MCS than the other CW. In this case, more coding bitsmay be transmitted/received than in the opposite case (e.g., a casewhere a resource having one more RBG is allocated to the CW having alower MCS than the other CW.

Accordingly, according to the second example of the present disclosure,9 RBGs may be allocated to a CW having a higher MCS, and 8 RBGs may beallocated to a CW having a (relatively) low MCS.

FIG. 19 is a diagram illustrating another example of a PRG for eachcodeword according to the present disclosure.

In FIG. 19, it is assumed that 5 PRGs are indicated/allocated to the UE,and that the MCS of CW #1 is higher than the MCS of CW #0. Unlike theexample of FIG. 19, when the MCSs of the two CWs are the same, more RBGsmay be allocated to CW #0 (or CW #1).

In a third example, as a method for minimizing retransmissions whenblockage occurs in one of two TRPs, each CW may be configured to beself-decodable. For a CW having a low MCS, the number of coding bitsthat may be transmitted may be smaller than that for a CW having a highMCS. Accordingly, from the viewpoint that each CW must beself-decodable, an additional RB may be allocated to a CW having a lowerMCS to transmit coding bits.

To this end, 8 RBGs may be allocated for a CW having a higher MCS, and 9RBGs may be allocated for a lower CW.

FIG. 20 is a diagram illustrating another example of a PRG for eachcodeword according to the present disclosure.

In FIG. 20, it is assumed that 5 PRGs are indicated/allocated to the UE,and that the MCS of CW #1 is higher than the MCS of CW #0. Unlike theexample of FIG. 20, when the MCSs of the two CWs are the same, more RBGsmay be allocated to CW #0 (or CW #1).

According to a fourth example, in the ‘interleaved PRGs’ of thesecond/third example described above, a CW to which a relatively largenumber of RBGs are allocated may be signaled based on the methodproposed in the first example (e.g., the signaling method based on thevalue of the NDI (and/or RV) field of TB #2). As an example, the CW towhich a relatively large number of RBGs are allocated may be signaled bysignaling a CW to be positioned at the top (in the frequency domain)according to the method proposed in the first example.

FIG. 21 is a diagram illustrating another example of a PRG for eachcodeword according to the present disclosure.

According to the example shown in FIG. 21, in the case of theinterleaved PRGs, an implicit rule based on MCS does not need to beseparately defined unlike in the second/third examples described above.

According to the various examples described above, two CWs may betransmitted from different TRPs, respectively. In this case, thepreferred RB position may differ between the TRPs according to thechannel gain or multiplexing with other UEs. In this case, according tothe above-described examples, the BS may dynamically configure/indicate,to the UE, the RB/RBG/PRG position at which the CW is transmittedthrough each TRP. As a result, according to the above-describedexamples, system throughput may be improved.

Additionally, in the first example described above, based on the NDIhaving the value of 0, the position of the frequency resource (e.g., theposition of the PRG or RGB having the highest index) for CW #0 may bedetermined to be higher (or greater) than the position of the frequencyresource (e.g., the position of the PRG or RGB having the highest index)for CW #1. Alternatively, based on the NDI having the value of 0, theposition of the frequency resource (e.g., the position of the PRG or RGBhaving the highest index) for CW #0 may be determined to be lower (orless) than the position of the frequency resource (e.g., the position ofthe PRG or RGB having the highest index) for CW #1.

In the second/third examples described above, the RBG and PRG sizes maybe 4 and 2, respectively, and one RBG may be divided into two PRGs. Inthis case, the two CWs may be assigned the same number (or the samesize) of BWs.

FIG. 22 is a diagram illustrating another example of a PRG for eachcodeword according to the present disclosure.

In FIG. 22, the first part (RBG-wise Interleaving) shows a PRGconfiguration for each codeword when NDI=0, 5 RBGs are allocated to aUE, and different CWs are transmitted in RBG units. As shown in FIG. 22,by dividing RBG #2 into two parts, the two CWs may have the same BW.

In FIG. 22, the second part (PRG-wise Interleaving) shows a PRGconfiguration for each codeword when different CWs are transmitted inPRG units.

The second example and the third example described above may beexclusive to each other. Accordingly, RBG allocation according to MCSmay be determined based on higher layer signaling (e.g., RRC, MAC-CE) orDCI. For example, when RBG allocation is determined by DCI, the RGBdistribution configuration may be determined based the NDI of the secondTB, and/or the RV of the second TB, and/or the MCS field of the secondTB.

2.3.2.2. Second RB Allocation Method

A UE configured with the PDSCH-rep-mode may (i) determine a (single)primary frequency position based on the FRA field, and (ii) determinetwo secondary frequency positions at which two CWs are to be transmittedbased on the NDI of the second TB, and/or the RV of the second TB,and/or the MCS field of the second TB based on the primary frequencyposition.

For operation according to the present disclosure, a downlink resourceallocation method defined by the following tables may be applied.However, the following is merely one downlink resource allocation methodapplicable to the present disclosure, and a different downlink resourceallocation method may be applied for the operation according to thepresent disclosure.

TABLE 32 5.1.2.2.2 Downlink resource allocation type 1 In downlinkresource allocation of type 1, the resource block assignment informationindicates to a scheduled UE a set of contiguously allocatednon-interleaved or interleaved virtual resource blocks within the activebandwidth part of size N_(BWP)

 PRBs except for the case when DCI format 1_0 is decoded in any commonsearch space in which case the size of CORESET 0 shall be used. Adownlink type 1 resource allocation field consists of a resourceindication value (RIV) corresponding to a starting virtual resourceblock ( RB_(start) ) and a length in terms of contiguously allocatedresource blocks L_(RBs). The resource indication value is defined by if(L_(RBs) − 1)≤└N_(BWP)

/2┘ then RIV = N_(RWP)

(L_(RBs) − 1) + RB_(start) else RIV = N_(BWP)

(N_(BWP)

 − L_(RBs) + 1) + (N_(BWP)

 − 1 − RB_(start)) where L_(RBs) ≥ 1 and shall not exceed N_(BWP)

 − RB_(start).

indicates data missing or illegible when filed

TABLE 33 When the DCI size for DCI format 1_0 in USS is derived from thesize of CORESET 0 but applied to another active BWP with size of N_(BWP)

, a downlink type

 resource block assignment field consists of a resource indication value(RIV) corresponding to a starting resource block RB_(start) =0,K,2·K,...,(N_(BWP)

 −1)·K and a length in terms of virtually contiguously allocatedresource blocks L

 = K,2·K,...,N_(BWP)

·K . The resource indication value is defined by: if (L′

−1)≤└N_(BWP)

/2┘ then RIV = N_(BWP)

(L′

−1)+RB′_(start) else RIV = N_(BWP)

(N_(BWP)

−L′

+1)+(N_(BWP)

−1−RB′_(start)) where L′

=L

/K , RB′_(start)=RB_(start)/K and where L′

 shall not exceed N_(BWP)

−RB′_(start) . if N_(BWP)

 > N_(BWP)

 , K is the maximum value from set {1, 2, 4, 8} which satisfies K ≤└N_(BWP)

 / N_(BWP)

┘ ; otherwise K = 1.

indicates data missing or illegible when filed

In the first example, when the above-described downlink resourceallocation type 1 is applied, the UE may first determine the primaryfrequency position based on the same/similar method as in conventionalcases. In addition, the UE may determine two secondary frequencypositions at which two CWs are to be transmitted with respect to theintermediate point of the primary frequency BW, based on the RV of thesecond TB.

In the present disclosure, the intermediate point of the primaryfrequency position may satisfy the equation given below. In the equationbelow, N_(BW), RV, and P may denote the BW at the primary frequencyposition, an RV value of the second TB, and a PRG size. In the equationbelow, K may be 1, or may be indicated/configured based on the BW at theprimary frequency position or higher layer signaling. Additionally, forsimplicity, an operation of utilizing the RV value for the second TBwill be described above. However, the operation may be extended to anoperation of utilizing at least one of the RV and/or MCS and/or NDIfields of the second TB according to an embodiment.

$\begin{matrix}{\min\left( {{\left\lfloor \frac{N_{BW}}{2} \right\rfloor + {K\; P \times \left( {{RV} - 1} \right)}},{N_{BW} - 1}} \right)} & \left\lbrack {{Equation}\mspace{14mu} 10} \right\rbrack\end{matrix}$

FIG. 23 is a diagram illustrating an example of a PRG for each codewordbased on an RV value according to the present disclosure.

As illustrated in FIG. 23, when the number of PRGs is 7, frequencyresource positions and BWs for CW #0 and CW #1 may be determined basedon the above equation. In this operation, it is assumed that the valueof K is set to 1. However, another value of K may be set/indicatedaccording to embodiments.

FIG. 24 is a diagram illustrating another example of a PRG for eachcodeword based on an RV value according to the present disclosure.

As illustrated in FIG. 24, when the number of PRGs is 6, whether toswitch the frequency resource positions for CW #0 and CW #1 may bedetermined based on the value of NDI.

FIG. 25 is a diagram illustrating another example of a PRG for eachcodeword based on an RV value according to the present disclosure.

According to the example of FIG. 25, the PRG configuration for eachcodeword given when the RV value is 2 may be the same as that given whenthe RV value is 3.

When K=1, if the number of PRGs is small, the difference in BW occupiedby CW #0 and CW #1 may be set large according to the RV value. On theother hand, when the number of PRGs is large, the difference in BWoccupied by each codeword may be set large. Thus, the value of K may bedetermined based on the BW and/or the number of PRGs. As an example, thevalue of K may be determined based on the total number of PRGs as shownin the table below. In the present disclosure, the details in thefollowing table are merely an example, and the value of K may bedetermined based on criteria/rules different from those is the followingtable.

TABLE 34 PRG K PRG < 16 1 16 <= PRG < 32 2 32 <= PRG < 64 4

2.3.3. Method for Allocating Slots for TDM PRGs Dynamically

A UE configured with the PDSCH-rep-mode may determine the position of aslot/symbol in which the UE is to receive CW #1 after receiving CW #0based on the NDI of the second TB, and/or the RV of the second TB,and/or the MCS field of the second TB defined in DCI.

In the present disclosure, for example, a TDMed PRG mode may beconfigured for the UE by the BS based on higher layer signaling and/orDCI. In other words, the UE for which the TDMed PRG mode is configuredby the BS set may perform an operation described later.

FIG. 26 is a diagram illustrating an example of slot allocation for eachcodeword applicable to the present disclosure.

According to FIG. 26, a UE (e.g., a UE for which a TDMed PRG mode isconfigured based on higher layer signaling and/or DCI) may receive the0-th CW, and then receive the 1st CW after X slots.

In the present disclosure, X may be determined by (i) preconfiguring oneor more values by higher layer signaling (e.g., RRC, MAC-CE), and (ii)selecting one of the configured values by DCI.

As an example for this operation, at least one of the NDI field of thesecond TB, and/or the RV field of the second TB, and/or the MCS field ofthe second TB in the DCI may be used. For example, {2, 4, 8, 16} may bepreconfigured by higher layer signaling (e.g., RRC), and 2 may beindicated/selected through the DCI. In this case, the size of the DCIfield used may be (variably) set based on the number of candidatesconfigured by higher layer signaling.

Additionally, in the present disclosure, the UE may expect the frequencypositions of CW #0 and CW #1 to be the same (for reduction of operationcomplexity).

2.3.4. UE Behaviors Related to PT-RS

In the present disclosure, a signal for estimating phase noise isreferred to as a phase tracking reference signal (PT-RS).

Basically, when the higher layer parameter phaseTrackingRS is configuredin the higher layer parameter DMRS-DownlinkConfig (or the higher layerparameter DMRS-UplinkConfig), the UE may receive the PT-RS, assumingthat the PT-RS is present. However, if (i) the layer parameterphaseTrackingRS is not configured, or (ii) the higher layer parameterphaseTrackingRS is configured, but a certain condition (e.g., i) thescheduled modulation and coding scheme (MCS) is lower than a certainlevel, or ii) the number of scheduled RBs is less than a certain value,or iii) the related random network temporary identifier (RNTI) isRA-RNTI (Random Access RNTI), system information RNTI (SI-RNTI), orpaging RNTI (P-RNTI)) is satisfied, the UE may assume that the PT-RS isnot present.

Regarding the UL PT-RS, a specific UL PT-RS transmission method for theUE may depend on whether transform precoding is enabled/disabled.However, in any cases, the UL PT-RS may be transmitted only within aresource block for the PUSCH. Specifically, when transform precoding isdisabled, the UL PT-RS may be mapped to subcarriers for the DMRS portrelated to the PT-RS port, and may be mapped to some of the resourceblocks allocated for PUSCH transmission based on the frequency density,which will be described below.

Regarding the DL PT-RS, the DL PT-RS may be transmitted only within aresource block for the PDSCH, and may be mapped to subcarriers for theDMRS port related to the PT-RS port, and may be mapped to some of theresource blocks allocated for PDSCH transmission based on the frequencydensity described below.

FIG. 27 is a diagram illustrating a time domain pattern of a PT-RSapplicable to the present disclosure.

As shown in FIG. 27, the PT-RS may have a different (time) patternaccording to the applied MCS level.

TABLE 35 Scheduled MCS Time density (L_(PT-RS)) I_(MCS) < ptrs-MCS₁PT-RS is not present ptrs-MCS1 ≤ I_(MCS) < ptrs-MCS2 4 ptrs-MCS2 ≤I_(MCS) < ptrs-MCS3 2 ptrs-MCS3 ≤ I_(MCS) < ptrs-MCS4 1

Here, time density 1 may correspond to Pattern #1 of FIG. 27, timedensity 2 may correspond to Pattern #2 of FIG. 27, and time density 4may correspond to Pattern #3 of FIG. 27.

Parameters ptrs-MCS1, ptrs-MCS2, ptrs-MCS3, and ptrs-MCS4 constitutingTable 35 may be defined by higher layer signaling.

The PT-RS according to the present disclosure may be mapped to andtransmitted on 1 subcarrier for every 1 RB, 1 subcarrier for every 2RBs, or 1 subcarrier for every 4 RBs. In this case, the frequency domainpattern (or frequency density) of the PT-RS as described above may beconfigured according to the size of the scheduled bandwidth.

TABLE 36 Scheduled bandwidth Frequency density (K_(PT-RS)) N_(RB) <N_(RB0) PT-RS is not present N_(RB0) ≤ N_(RB) < N_(RB1) 2 N_(RB1) ≤N_(RB) 4

Here, frequency density 2 may correspond to a frequency domain patternin which the PT-RS is mapped to and transmitted on one subcarrier forevery two RBs, and frequency density 4 may correspond to a frequencydomain pattern in which the PT-RS is mapped to and transmitted on onesubcarrier for every four RBs.

In the configuration above, N_(RS0) and N_(RS1), which are referencevalues of the scheduled bandwidth for determining the frequency density,may be defined by higher layer signaling.

Based on the PT-RS as described above, the UE may operate as follows.

A UE configured with the PDSCH-rep-mode may determine the frequencyposition of the PT-RS for each CW based on the RBs through which therespective CWs are transmitted, based on (i) theindication/configuration that the two CWs are transmitted at differentresources or (ii) the indication/configuration that the two CWs aretransmitted at some resources in an overlapping manner.

The above-described configurations may be applied not only to the UE forwhich the PDSCH-rep-mode is configured, but also to UEs for which themode is not configured. That is, irrespective of the PDSCH-rep-modeconfiguration, when it is indicated/configured to the UE by the BS thattwo CWs are transmitted at different resources, the UE may determine thefrequency position of the PT-RS for each CW based on the RBs in whicheach CW is transmitted.

For reference, the resource position (in particular, the frequencyposition) at which the DL PT-RS is transmitted and received may bedetermined based on the table below.

TABLE 37 For the purpose of PT-RS mapping, the resource blocks allocatedfor PDSCH transmission are numbered from 0 to N_(RB)−1 from the lowestscheduled resource block to the highest. The corresponding subcarriersin this set of resource blocks are numbeied in increasing order startingfrom the lowest frequency from 0 to N_(sc) ^(RB)N_(RB)−1. Thesubcarriers to which the UE shall assume the PT-RS is mapped are givenby where${k = {k_{ref}^{RE} + {\left( {{tK}_{{PT} - {RS}} + k_{ref}^{RB}} \right)N_{sc}^{RB}}}}{k_{ref}^{RB} = \left\{ \begin{matrix}{n_{RNTI}{mod}K_{{PT} - {RS}}} & {{{if}N_{RB}{mod}K_{{FT} - {RS}}} = 0} \\{n_{RNTI}{{mod}\left( {N_{RB}{mod}K_{{PT} - {RS}}} \right)}} & {otherwise}\end{matrix} \right.}$ i = 0,1,2, . . . k_(ref) ^(RE) is given by Table7.4 1.1.2-1 for the DM-RS port associated with the PT-RS port accordingto TS 38.214. If the higher-layer parameter resourceElementOffset in thePTRS-DownlinkConfig IE is not configured, the column corresponding to‘offset00’ shall be used. n_(RNTI) is the RNTI associated with the DCIscheduling the transmission N_(RB) is the number of resource blocksscheduled K_(PT-RS) ∈{2,4} is given by TS 38.214.

TABLE 7.4.1.2.2-1 The parameter k_(ref) ^(RE). k_(ref) ^(RE) DM-RSConfiguration type 1 DM-RS Configuration type 2 DM-RS antenna portresourceElementOffset resourceElementOffset p offset00 offset01 offset10offset11 offset00 offset01 offset10 offset11 1000 0 2 6 8 0 1 6 7 1001 24 8 10 1 6 7 0 1002 1 3 7 9 2 3 8 9 1003 3 5 9 11 3 8 9 2 1004 — — — — 45 10 11 1005 — — — — 5 10 11 4

In the present disclosure, it may be assumed that TRPs #1 and #2transmit CWs #0 and #1, respectively. In this case, when the BSindicates/configures to the UE that the (maximum) number of PT-RS portsis 2, TRPs #1 and #2 may each transmit PT-RS to the UE.

In this case, when the RB position at which the PT-RS is transmitted isdetermined based on the RBs allocated to the UE, a specific TRP may failto transmit the PT-RS or the frequency density of the PT-RS may belowered. As a result, the performance of estimating the common phaseerror (CPE) based on a signal received from the TRP by the UE may bedegraded.

FIG. 28 is a diagram illustrating another example of a PRG for eachcodeword according to the present disclosure.

In FIG. 28, when the PRG size is 2 and the PT-RS frequency density is 4,a specific TRP (e.g., TRP #2) may fail to transmit the PT-RS. To addressthis issue, the RB position of the PT-RS for TRP #1 may be determinedbased on the RBs allocated to TRP #1 (or the RBs through which CW #1 istransmitted). Similarly, the RB position of the PT-RS for TRP #2 may bedetermined based on the RBs allocated to TRP #2 (or the RBs throughwhich CW #1 is transmitted). To this end, the N RBs allocated to eachTRP may be (re)indexed from 0 to N−1, and an RB through which the PT-RSis transmitted may be determined from among the N RBs based on themethod described above.

The first part (e.g., the leftmost block) and the second part (e.g., thesecond block from the left) of FIG. 28 illustrate configuration ofCW-wise grouping of PRGs (or RBGs) indicated/configured to the UE. TheUE may determine the frequency position of the PT-RS within each groupbased on the existing method for determining the PT-RS frequencyposition. The second part (e.g., the second block from the left) and thethird part (e.g., the third blocks from the left) of FIG. 28 illustraterecovering the original positions of PRGs (or RBGs).

2.3.5. Method for Indicating DMRS Ports of a Specific Codeword (e.g., CW#1) Dynamically

2.3.5.1. First DMRS Port Indication Method

When two CWs indicated by DCI are transmitted at different resources (orthe two CWs are transmitted at the same resource or partiallyoverlapping resources), a UE configured with the PDSCH-rep-mode maydetermine the DMRS ports related to (or associated with) the respectiveCWs based on higher layer signaling (e.g., RRC, MAC-CE, etc.) and/or theDCI.

As a specific example, the DMRS port(s) for CW #0 may beconfigured/determined based on a first field (e.g., a field related toantenna port(s)) of the DCI, and the DMRS port(s) for CW #1 may beconfigured/determined based on a second field (e.g., at least one of theantenna port(s) related field, and/or the NDI field of TB #2, and/or theMCS field (of TB #2), and/or the RV field (of TB #2)) of the DCI. Asanother example, DMRS ports information for CW #0 and CW #1 may bejoint-encoded and configured/determined based on a specific field of theDCI. As an example, the DMRS ports information for CW #0 and CW #1 maybe configured/determined based on at least one of the antenna port(s)related field, and/or the NDI field of TB #2, and/or the MCS field of(TB #2), and/or the RV field (TB #2).

In this case, when the UE refers to the MCS table, the UE may expectthat only one codeword is enabled even if two CWs are enabled.

All the embodiments described in section 2.3.5 are not limited to the UEfor which the PDSCH-rep-mode is configured, and may be extendedirrespective of whether the mode is configured. For example, the UE mayoperate based on all the embodiments described in section 2.3.5regardless of the PDSCH-rep-mode configuration for the UE even if a TCIstate or a plurality of TCI states including a plurality of RS sets isconfigured/indicated to the UE.

FIG. 29 is a diagram illustrating an example of a PRG configuration foreach TRP according to the present disclosure.

In FIG. 29, in the case of disjoint PRGs, two CWs may share some DMRSport indexes unlike in the case of overlapped PRGs. Further, the numberof DMRS ports (e.g., # of layers) may be set to be the same or differentbetween the CWs.

Accordingly, the operation of classifying the indicated DMRS ports foreach CW based on the mapping method defined in the conventional standard(e.g., CW2 layer mapping rule) may be inappropriate.

Therefore, according to the present disclosure, the BS needs toindicate, to the UE, separate DMRS ports for each of CW #0 and CW #1. Inaddition, according to the UE behavior based on the conventional MCStable, when the number of CWs is 2, the UE uses a mapping method definedin the conventional standard (e.g., CW2 layer mapping rule). Therefore,according to the present disclosure, the UE may no longer use theoperation. Accordingly, according to the present disclosure, even whentwo CWs are enabled, the UE may interpret the MCS table, assuming thatonly one codeword is enabled.

According to a first example, DMRS ports for CW #0 may be determinedbased on an antenna port(s) related field. In addition, DMRS ports forCW #1 may be determined based on 3 bits of least significant bits (LSB)of the MCS for TB #2 and 2 bits of the RV for TB #2. According to thisexample, 5 bits for indicating the DMRS ports for CW #1 may besupported. Accordingly, according to the above example, most of the DMRStable (e.g., Tables 14 to 16) may be supported without adding a separateDCI field or changing the DMRS tables.

According to a second example, in the case where the BS is allowed toset/indicate the modulation order of a specific CW through the RV fieldin the first example, 5 bits of the MCS field may be used toconfigure/indicate DMRS ports for CW #1. In the case of Table 14, 4 bitsare required, and thus the MSB 4 bits of the MCS may be used toconfigure/indicate the DMRS ports for CW #1. In the case of Tables 15and 16, 5 bits are required, and thus all bit information of the MCS maybe used to configure/indicate DMRS ports for CW #1.

According to a third example, the UE may operate as follows.

When TB #1 and TB #2 are enabled at the same time, a UE supporting theRel-15 NR system may operate with reference to a column for 2 CWs in theDMRS table (e.g., Two Codewords: Codeword 0 enabled, Codeword 1enabled). On the other hand, according to the first and second examplesdescribed above, even when two TBs are enabled at the same time, the UEmay operate with reference to a column for 1 CW (e.g., One Codeword:Codeword 0 enabled, Codeword 1 disabled) in the DMRS table. As a result,when the operation is based on the current DMRS table, the first/secondexamples may not support rank 5 or higher.

Accordingly, in the third example, in order to address this issue, acolumn for 1 CW in the conventional DMRS table (e.g., One Codeword:Codeword 0 enabled, Codeword 1 disabled) may include information forDMRS ports of rank 5 or higher.

As an example, in the case of Table 15, value=31 in the column for 1 CW(e.g., One Codeword: Codeword 0 enabled, Codeword 1 disabled) may bedefined to configure/indicate DMRS ports 0-4.

As another example, based on at least one of the antenna port(s) field,and/or the NDI field of TB #2, and/or the MCS field (of TB #2), and/orthe RV field (of TB #2), the DMRS table referred to by CW #0 may beextended to more than 32 (e.g., 64) columns for 1 CW (e.g., OneCodeword: Codeword 0 enabled, Codeword 1 disabled).

As another example, based on at least one of the NDI field of TB #2,and/or the MCS (of TB #2), and/or the RV of (TB #2), the BS mayconfigure/indicate a column for 1 CW (e.g., One Codeword: Codeword 0enabled, Codeword 1 disabled) or a column for 2 CWs (e.g., TwoCodewords: Codeword 0 enabled, Codeword 1 enabled) referred to by the UEfor CW #0 in the DMRS table.

According to the third example, CW #0 may substantially include two CWs.Similarly, CW #1 may substantially include two CWs.

However, these features may not conform to the principle or premise thatCW #0 and CW #1 are generated from the same information sequence. Inaddition, considering CW #0-0/CW #0-1 from TRP #0 and CW #1-0/CW #1-1from TRP #1 (where CW #0-0 and CW #1-0 may be generated from the sameinformation sequence), the aforementioned configuration may be awkward.

Therefore, according to the third example, a configuration including CW#0/CW #1 from TRP #0 and CW #0′/CW #1′ from TRP #1 rather than theabove-described features may be natural. Accordingly, in the thirdexample, the BS may schedule the PDSCH transmitted from each TRP usingtwo DCIs.

In the above-described configurations, CW #0 and CW #1 may be swappedwith each other. In other words, according to another embodiment, thefeatures for CW #0 described above may be applied to CW #1, and thefeatures for CW #1 described above may be applied to CW #0.

In the above-described configurations, the CW using the DMRS portsconfigured/indicated by the antenna port(s) field may be a CW associatedwith the DCI field (e.g., MCS, RV, NDI) used in determining the TB size.Further, the DMRS ports of the other CW may be determined based on atleast one of the MCS field, and/or the RV field, and/or the NDI field ofthe other CW. For example, when the DCI field of TB #2 is used indetermining the TB size, the DMRS ports of CW #1 may be determined basedon the antenna port(s) field. And, the DMRS ports of CW #0 may beconfigured/indicated based on the MCS field (e.g., 5 bits) of TB #1.

2.3.5.2. Second DMRS Port Indication Method

In the first DMRS port indication method described above, the UE mayexpect that the number of front-load symbols of CW #0 and CW #1 (e.g., #of front-load symbols) and/or the number of DMRS CDM groups without data(e.g., # of DMRS CDM group(s) without data) are equal to each other. Tothis end, the DMRS table referred to by the UE for CW #1 may beconfigured/indicated based on # of DMRS CDM group(s) without data for CW#0.

As an example, it is assumed that different TRPs each transmit a signal(or layer) to one UE on the same OFDM symbol. In this case, in order tolower the UE complexity and the BS scheduling complexity, the BS maylimit (or configure) the number of front-load symbols and the number ofDMRS CDM group(s) without data are the same between the two CWs. Whenthe DMRS table referred to by the UE for CW #1 is designed based on thislimitation, the number of bits required to indicate/configure the DMRSports for CW #1 may be reduced.

More specifically, in Table 17, the column for 1 CW (e.g., One Codeword:Codeword 0 enabled, Codeword 1 disabled) may be divided into (i) value=0to 23 (24 rows in total when the number of front-load symbols is 1) and(ii) value=24 to 57 (34 rows in total when the number of front-loadsymbols is 2), by the number of front-load symbols. Here, the case wherethe number of front-load symbols is 2 is modified to 32 rows (by, forexample, deleting two rows out of the 34 rows), the BS mayindicate/configure the DMRS pots of CW #1 using 5 bits.

Alternatively, when the number of front-load symbols as well as thenumber of DMRS CDM groups without data is the same, the maximum numberof rows that the BS should classify through DCI may be set to 24 (e.g.:# of DMRS CDM group(s)=3, # of front-load symbols=2). In this case, theBS may indicate/configure the DMRS ports of a specific CW using the5-bit information without modifying the existing DMRS table.

2.3.5.3. Third DMRS Port Indication Method

In the first DMRS port indication method described above, in the casewhere two CWs are transmitted at the same resource or partiallyoverlapped resources, the UE may expect that the DMRS ports (or layers)belonging to CW #X (e.g., X=0 or 1) are included in one DMRS CDM group.In other words, the UE may not expect a configuration in which the DMRSports (or layers) belonging to CW #X (e.g., X=0 or 1) are included in aplurality of different DMRS CDM groups. In addition, in the above case,the UE may expect only the case where the number of CDM groups isgreater than or equal to 2.

Accordingly, according to the third DMRS port indication method of thepresent disclosure, the DMRS table referred to by the UE for CW #0and/or CW #1 may be redesigned based on the above features.

The above-described configuration may be applied only to DMRSconfiguration type 1 in which the number of DMRS CDM groups is 2.

Alternatively, in the case of DMRS configuration type 2 in which thenumber of DMRS CDM groups is 3, the above-described configuration may bemodified as follows. Specifically, in the first DMRS port indicationmethod described above, the UE may expect that the DMRS CDM group towhich the DMRS ports (or layers) of CW #0 belong is different from theDMRS CDM group to which the DMRS ports (or layers) of CW #1 belong. Inaddition, the UE may expect only the case where the number of CDM groupsis greater than or equal to 2. Based on the above-described features,the DMRS table referred to by the UE for CW #0 and/or CW #1 may beredesigned.

Specifically, when two CWs are transmitted at the same resource or atsome resources in an overlapping manner, the DMRS ports (or layers) ofthe two CWs should belong to different DMRS CDM groups, respectively. Asan example, in Table 14, the BS cannot configure/indicate value=9 (DMRSports=0-2), 10 (DMRS ports=0-3), and 11 (DMRS ports=0,2) to the UE forCW #0. In addition, in this case, two or more CDM groups are basicallyrequired. Accordingly, the UE may expect only the case where the numberof CDM groups is greater than or equal to 2. When a DMRS table referredto by the UE for CW #0/#1 is designed based on the above-describedfeatures, the BS may reduce the number of required DCI bits.

In a first example, when the above-described features are applied toTable 14, the number of rows referred to by the UE for CW #0/#1 in theDMRS table may be reduced to 6 (e.g., value=3 to 8 in Table 14).

According to the first example, the BS may indicate/configure the DMRSports for CW #0/#1 to the UE through a separate DCI field, respectively.As an example, the BS may (i) indicate/configure the DMRS ports of CW #0based on the antenna port field, and (ii) indicate/configure the DMRSports of CW #1 based on at least one of the RV field of TB #2, and/orthe NDI field (of TB #2), and/or the MCS field (of TB #2).

In a second example, the DMRS ports referred to by the UE for CW #0/#1may be joint-encoded together and may be defined as shown in the tablebelow. In this case, when a limitation that CW #0 and CW #1 shall notuse the same DMRS port index is applied, the number of rows in the tablemay be further reduced. As a result, the BS may additionally reduce thenumber of DCI bits required to represent each of the DMRS ports of thetwo CWs. The DMRS ports of the two CWs may be indicated based on atleast one of the antenna port(s) field, and/or the NDI field of TB #2,and/or the RV field (of TB #2), and/or the MCS field (of TB #2).

TABLE 38 # of DMRS group DMRS ports of DMRS ports of Value without dataCW#0 CW#1 0 2 0, 1 2 1 2 0 2, 3 2 2 0, 1 2, 3 3 2 0 2

Unlike the second DMRS port indication method described above, accordingto the third DMRS port indication method, the number of rows referred toby the UE for CW #0 as well as CW #1 in the DMRS table may be reduced.

2.3.5.4. Fourth DMRS Port Indication Method

When a UE configured with the PDSCH-rep-mode receives anindication/configuration that one of the two CWs is disabled from the BSthrough DCI, the UE may determine the DMRS ports of the enabled CW basedon an existing DMRS table (e.g., Tables 14 to 17) that is based on theantenna port field.

More specifically, when CW #1 is disabled, the UE may expect that onlyone specific TRP/beam transmits CW #0 even though the PDSCH-rep-mode isconfigured therefor. In addition, the UE may expect that the otherTRP/beams do not transmit CW #1. The DMRS ports of CW #0 may bedetermined based on the existing DMRS table (e.g., Tables 14 to 17) thatis based on the antenna port field.

FIG. 30 is a diagram schematically illustrating an exemplary operationof a UE and a base station (e.g., an object including TRP #1 and TRP #2)applicable to the present disclosure.

In FIG. 30, PDSCH #1 and PDSCH #2 may be composed of coded bitsgenerated from the same information sequence (or the same TB).Additionally, PDSCH #1 and PDSCH #2 in the corresponding configurationmay be extended to CW #0 and CW #1, respectively.

First, the PDSCH-rep-mode may be configured for the UE by the BS. Asdescribed above in section 2.1.1.1, the configuration may be establishedthrough one or more of the following methods.

-   -   1) Establishing the configuration through higher layer signaling        (e.g., RRC and/or MAC-CE, etc.) of the BS;    -   2) (i) DCI including CRC scrambled with RNTI for PDSCH-rep-mode        is indicated to the UE, and/or (ii) the BS indicates a TCI state        (or two TCI states) including two RS sets to the UE through the        DCI, and/or (iii) the PDSCH-rep-mode is configured for the UE by        higher layer signaling; and    -   3) (i) The BS indicates/configures two TCI states to the UE        through DCI, and (ii) the number of code division multiplexing        (CDM) groups allocated through the DCI is 1.

In other words, when the PDSCH-rep-mode is configured based on method 1)between the above-described methods, the UE may additionally receive aPDCCH for scheduling PDSCH #1 and/or PDSCH #2 from TRP #1 or TRP #2.

Alternatively, when the PDSCH-rep-mode is to be configured based onmethod 2) among the above-described methods, the PDSCH-rep-mode may beconfigured for the UE based on the determination that (i) the DCIincluded in a PDCCH for scheduling PDSCH #1 and/or PDSCH #2 receivedfrom TRP #1 or TRP #2 includes a CRC scrambled with an RNTI for thePDSCH-rep-mode, and/or (ii) a TCI state (or two TCI states) includingtwo RS sets is indicated.

In addition, based on at least one of the methods according to sections2.1.2 to 2.1.4 or 2.2.1 to 2.2.3 above, the UE may receive PDSCH #1 (orCW #0 or TB #1) and/or PDSCH #2 (or CW #1 or TB #2) transmitted from TRP#1 and/or TRP #2.

More specifically, the UE may determine whether the frequency resourceallocation scheme for two CWs scheduled by a single PDCCH is localizedPRGs or distributed PRGs, based on various methods disclosed in section2.3.1. In addition, the UE may receive a signal indicating specificfrequency resource allocation and perform related operations based onvarious methods disclosed in section 2.3.2.

When it is indicated to the UE that the two CWs are transmittedaccording to the TDM scheme, the UE may receive a signal indicating timeresource allocation for the CWs and perform related operations, based onvarious methods disclosed in section 2.3.3.

When the two CWs are transmitted to the UE in different frequencyregions, the UE may determine a frequency position of the PT-RS for eachCW based on various methods disclosed in section 2.3.4.

When the two CWs are transmitted to the UE in different frequencyregions, the UE may receive a signal indicating DMRS port indexes ofeach CW and perform and related operations, based on various methodsdisclosed in section 2.3.5.

As more specific methods, the methods disclosed above in sections 2.1,2.2 and 2.3 may be applied.

FIG. 31 is a diagram schematically illustrating the operation of a UEand a BS according to an example of the present disclosure, FIG. 32 is aflowchart of an operation of the UE according to an example of thepresent disclosure, and FIG. 33 is a flowchart of an operation of the BSaccording to an example of the present disclosure.

The UE may receive downlink control information (DCI) including aplurality of transmission configuration indicator (TCI) states from theBS (S3110, S3210). In a corresponding operation, the BS may transmit theDCI to the UE (S3110, S3310).

In the present disclosure, each of the plurality of TCI states may berelated to one RS set.

The UE may obtain, from the BS, mode information related to a first modein which a plurality of data based on the same information aretransmitted.

As an example applicable to the present disclosure, the first mode mayinclude a multi-TRP-based URLLLC (ultra-reliable low latencycommunication) mode. As another example, the mode information may berelated to one of the first mode or a second mode including amulti-TRP-based eMBB (enhanced mobile broadband) mode.

As an example applicable to the present disclosure, the UE may receivethe mode information through higher layer signaling including RRCsignaling (S3120, S3220). In a corresponding operation, the BS maytransmit the mode information to the UE through higher layer signaling(S3120, S3320). In this case, the transmission and reception of the modeinformation may be performed before or after the transmission andreception of the above-described DCI in the time domain.

Alternatively, as another example applicable to the present disclosure,the UE may obtain the information based on DCI including a cyclicredundancy check (CRC) scrambled with a radio network temporaryidentifier (RNTI) related to the first mode. In other words, the UE mayobtain the mode information related to the first mode without additionalsignaling.

Based on the DCI and the mode information, the UE may assume that (i)data reception via a plurality of physical downlink shared channels(PDSCHs) is scheduled by the DCI, and (ii) data received via theplurality of PDSCHs is based on the same information (S3130, S3230).

Subsequently, the UE may obtain resource information about the pluralityof PDSCHs based on the assumption (S3140, S3240).

In the present disclosure, the DCI may include two TCI states, and theplurality of PDSCHs may include two PDSCHs.

In the present disclosure, based on the size of precoding resource blockgroup (PRG) bundling configured for the UE, (i) the resource informationabout the plurality of PDSCHs may be determined based on a localized PRGconfiguration according to the size of PRG bundling configured with awideband PRG, or (ii) the resource information about the plurality ofPDSCHs may be determined based on an interleaved PRG configurationaccording to the size of PRG bundling set to 2 or 4.

These features may be generalized as follows. For the wideband PRG,first RBs among the RBs allocated to the UE may be assigned to a firstTCI state, and the remaining second RBs may be assigned to a second TCIstate. In this case, each of the first RBs and the second RBs may beconfigured as contiguous RBs. Alternatively, for the PRG size set to 2or 4, even PRGs among the PRGs allocated to the UE may be assigned tothe first TCI state, and odd PRGs may be assigned to the second TCIstate.

As another example, the DCI may include information for two transportblocks (TBs). In this case, the resource information about the twoPDSCHs may be determined based on one of the spatial divisionmultiplexing (SDM), time division multiplexing (TDM), and frequencydivision multiplexing (FDM) modes based on information related to one ofthe two TBs related to the DCI.

As another example, the resource information about the two PDSCHs mayinclude frequency resource information about each of the two PDSCHsdetermined based on the information related to one TB in the informationfor two TBs included in the DCI.

As a specific example, based on the configuration of PRG bundlingconfigured for the UE, a bundling mode of one of the localized PRG orthe interleaved PRG may be configured for the UE. In addition, based on(i) the configured PRG mode and (ii) the information related to the oneTB, frequency resource information for each of the two PDSCHs may beconfigured differently.

In this case, when an odd number of total resource block group (RBG)sizes are allocated to the UE, resources may be allocated for thefirst/second PDSCHs according to one of the following schemes:

-   -   (i) One more RBG is allocated for the first PDSCH based on        configuration in which a first MCS for the first PDSCH between        the PDSCHs being higher than a second MCS for the second PDSCH        between the PDSCHs;    -   (ii) One more RBG is allocated for the second PDSCH based on the        first MCS being higher than the second MCS;    -   (iii) One more RBG is allocated for the first PDSCH or the        second PDSCH based on the first MCS being the same as the second        MCS; or    -   (iv) One more RBG is allocated for one PDSCH determined based on        information related to the one TB between the PDSCHs.

In the present disclosure, the information related to the one TB may beinformation related to a TB corresponding to a second order between thetwo TBs. Herein, the information related to the TB corresponding to thesecond order may include at least one of the followings:

-   -   NDI related to the second TB;    -   RV related to the second TB; and    -   MCS related to the second TB.

As another example, the resource information about the two PDSCHs mayinclude time resource information about each of the two PDSCHsdetermined based on information related to one TB in the information forthe two TBs included in the DCI.

Here, the time resource information may be related to an offset betweenthe time resource positions for the two PDSCHs. In addition, frequencyresources for the two PDSCHs may be configured identically.

Based on the resource information about a plurality of PDSCHs determinedbased on the method described above, the UE may obtain data informationvia a plurality of PDSCHs (S3150, S3250). In a corresponding operation,the BS may transmit the data information to the UE through resourcesindicated by the resource information about the plurality of PDSCHs(S3150, S3330).

In the present disclosure, obtaining the data information by the UE viathe two PDSCHs may include (i) obtaining first demodulation referencesignal (DMRS) port information for a first PDSCH based on antenna portrelated information included in the DCI, (ii) obtaining second DMRS portinformation for a second PDSCH based on information related to one ofthe two TBs related to the DCI, and (iii) receiving the data informationvia the first PDSCH and the second PDSCH based on the first DMRS portinformation and the second DMRS port information.

In the present disclosure, the two PDSCHs may be related to two TCIstates, respectively, and the two PDSCHs may be received from differenttransmission reception points.

In the present disclosure, the UE may additionally (i) determine afrequency position of a phase tracking reference signal (PT-RS) for eachof the PDSCHs independently based on frequency resources for each of thetwo PDSCHs, and (ii) receive the PT-RS for each of the PDSCHs based onthe frequency position of the PT-RS for each of the PDSCHs.

In other words, a PT-RS resource mapping pattern for each of the PDSCHsmay be determined independently based on RB resources allocated inassociation with each TCI state. Accordingly, the frequency density ofthe PT-RS for each of the PDSCHs may be determined based on the numberof RGs associated with each TCI state.

It is apparent that examples of the above-described proposed method mayalso be included as one of the implementation methods of the presentdisclosure, and accordingly may be regarded as a kind of proposedmethod. In addition, the above-described proposed methods may beimplemented independently, or some of the proposed methods may becombined (or merged) to be implemented. A rule may be defined that theBS shall deliver, to the UE, the information on whether to apply theproposed methods (or information on the rules of the proposed methods)through a predefined signal (e.g., a physical layer signal or a higherlayer signal).

3. Example of Communication System to which the Present Disclosure isApplied

The various descriptions, functions, procedures, proposals, methods,and/or operation flowcharts of the present disclosure described hereinmay be applied to, but not limited to, various fields requiring wirelesscommunication/connectivity (e.g., 5G) between devices.

More specific examples will be described below with reference to thedrawings. In the following drawings/description, like reference numeralsdenote the same or corresponding hardware blocks, software blocks, orfunction blocks, unless otherwise specified.

FIG. 34 illustrates a communication system 1 applied to the presentdisclosure.

Referring to FIG. 34, the communication system 1 applied to the presentdisclosure includes wireless devices, BSs, and a network. A wirelessdevice is a device performing communication using radio accesstechnology (RAT) (e.g., 5G NR (or New RAT) or LTE), also referred to asa communication/radio/5G device. The wireless devices may include, notlimited to, a robot 100 a, vehicles 100 b-1 and 100 b-2, an extendedreality (XR) device 100 c, a hand-held device 100 d, a home appliance100 e, an IoT device 100 f, and an artificial intelligence (AI)device/server 400. For example, the vehicles may include a vehiclehaving a wireless communication function, an autonomous driving vehicle,and a vehicle capable of vehicle-to-vehicle (V2V) communication. Herein,the vehicles may include an unmanned aerial vehicle (UAV) (e.g., adrone). The XR device may include an augmented reality (AR)/virtualreality (VR)/mixed reality (MR) device and may be implemented in theform of a head-mounted device (HMD), a head-up display (HUD) mounted ina vehicle, a television (TV), a smartphone, a computer, a wearabledevice, a home appliance, a digital signage, a vehicle, a robot, and soon. The hand-held device may include a smartphone, a smartpad, awearable device (e.g., a smartwatch or smartglasses), and a computer(e.g., a laptop). The home appliance may include a TV, a refrigerator, awashing machine, and so on. The IoT device may include a sensor, asmartmeter, and so on. For example, the BSs and the network may beimplemented as wireless devices, and a specific wireless device 200 amay operate as a BS/network node for other wireless devices.

The wireless devices 100 a to 100 f may be connected to the network 300via the BSs 200. An AI technology may be applied to the wireless devices100 a to 100 f, and the wireless devices 100 a to 100 f may be connectedto the AI server 400 via the network 300. The network 300 may beconfigured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g.,NR) network. Although the wireless devices 100 a to 100 f maycommunicate with each other through the BSs 200/network 300, thewireless devices 100 a to 100 f may perform direct communication (e.g.,sidelink communication) with each other without intervention of theBSs/network. For example, the vehicles 100 b-1 and 100 b-2 may performdirect communication (e.g. V2V/vehicle-to-everything (V2X)communication). The IoT device (e.g., a sensor) may perform directcommunication with other IoT devices (e.g., sensors) or other wirelessdevices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b, and 150 c may beestablished between the wireless devices 100 a to 100 f/BS 200 andbetween the BSs 200. Herein, the wireless communication/connections maybe established through various RATs (e.g., 5G NR) such as UL/DLcommunication 150 a, sidelink communication 150 b (or, D2Dcommunication), or inter-BS communication (e.g. relay or integratedaccess backhaul (IAB)). Wireless signals may be transmitted and receivedbetween the wireless devices, between the wireless devices and the BSs,and between the BSs through the wireless communication/connections 150a, 150 b, and 150 c. For example, signals may be transmitted and receivedon various physical channels through the wirelesscommunication/connections 150 a, 150 b and 150 c. To this end, at leasta part of various configuration information configuring processes,various signal processing processes (e.g., channel encoding/decoding,modulation/demodulation, and resource mapping/demapping), and resourceallocation processes, for transmitting/receiving wireless signals, maybe performed based on the various proposals of the present disclosure.

4. Example of Wireless Device to which the Present Disclosure is Applied

FIG. 35 illustrates wireless devices applicable to the presentdisclosure.

Referring to FIG. 35, a first wireless device 100 and a second wirelessdevice 200 may transmit wireless signals through a variety of RATs(e.g., LTE and NR). {The first wireless device 100 and the secondwireless device 200} may correspond to {the wireless device 100 x andthe BS 200} and/or {the wireless device 100 x and the wireless device100 x} of FIG. 35.

The first wireless device 100 may include one or more processors 102 andone or more memories 104, and further include one or more transceivers106 and/or one or more antennas 108. The processor(s) 102 may controlthe memory(s) 104 and/or the transceiver(s) 106 and may be configured toimplement the descriptions, functions, procedures, proposals, methods,and/or operation flowcharts disclosed in this document. For example, theprocessor(s) 102 may process information in the memory(s) 104 togenerate first information/signals and then transmit wireless signalsincluding the first information/signals through the transceiver(s) 106.The processor(s) 102 may receive wireless signals including secondinformation/signals through the transceiver(s) 106 and then storeinformation obtained by processing the second information/signals in thememory(s) 104. The memory(s) 104 may be connected to the processor(s)102 and may store various pieces of information related to operations ofthe processor(s) 102. For example, the memory(s) 104 may store softwarecode including instructions for performing all or a part of processescontrolled by the processor(s) 102 or for performing the descriptions,functions, procedures, proposals, methods, and/or operation flowchartsdisclosed in this document. The processor(s) 102 and the memory(s) 104may be a part of a communication modem/circuit/chip designed toimplement RAT (e.g., LTE or NR). The transceiver(s) 106 may be connectedto the processor(s) 102 and transmit and/or receive wireless signalsthrough the one or more antennas 108. Each of the transceiver(s) 106 mayinclude a transmitter and/or a receiver. The transceiver(s) 106 may beinterchangeably used with radio frequency (RF) unit(s). In the presentdisclosure, the wireless device may be a communicationmodem/circuit/chip.

The second wireless device 200 may include one or more processors 202and one or more memories 204, and further include one or moretransceivers 206 and/or one or more antennas 208. The processor(s) 202may control the memory(s) 204 and/or the transceiver(s) 206 and may beconfigured to implement the descriptions, functions, procedures,proposals, methods, and/or operation flowcharts disclosed in thisdocument. For example, the processor(s) 202 may process information inthe memory(s) 204 to generate third information/signals and thentransmit wireless signals including the third information/signalsthrough the transceiver(s) 206. The processor(s) 202 may receivewireless signals including fourth information/signals through thetransceiver(s) 106 and then store information obtained by processing thefourth information/signals in the memory(s) 204. The memory(s) 204 maybe connected to the processor(s) 202 and store various pieces ofinformation related to operations of the processor(s) 202. For example,the memory(s) 204 may store software code including instructions forperforming all or a part of processes controlled by the processor(s) 202or for performing the descriptions, functions, procedures, proposals,methods, and/or operation flowcharts disclosed in this document. Theprocessor(s) 202 and the memory(s) 204 may be a part of a communicationmodem/circuit/chip designed to implement RAT (e.g., LTE or NR). Thetransceiver(s) 206 may be connected to the processor(s) 202 and transmitand/or receive wireless signals through the one or more antennas 208.Each of the transceiver(s) 206 may include a transmitter and/or areceiver. The transceiver(s) 206 may be interchangeably used with RFunit(s). In the present disclosure, the wireless device may be acommunication modem/circuit/chip.

Now, hardware elements of the wireless devices 100 and 200 will bedescribed in greater detail. One or more protocol layers may beimplemented by, not limited to, one or more processors 102 and 202. Forexample, the one or more processors 102 and 202 may implement one ormore layers (e.g., functional layers such as physical (PHY), mediumaccess control (MAC), radio link control (RLC), packet data convergenceprotocol (PDCP), RRC, and service data adaptation protocol (SDAP)). Theone or more processors 102 and 202 may generate one or more protocoldata units (PDUs) and/or one or more service data Units (SDUs) accordingto the descriptions, functions, procedures, proposals, methods, and/oroperation flowcharts disclosed in this document. The one or moreprocessors 102 and 202 may generate messages, control information, data,or information according to the descriptions, functions, procedures,proposals, methods, and/or operation flowcharts disclosed in thisdocument and provide the messages, control information, data, orinformation to one or more transceivers 106 and 206. The one or moreprocessors 102 and 202 may generate signals (e.g., baseband signals)including PDUs, SDUs, messages, control information, data, orinformation according to the descriptions, functions, procedures,proposals, methods, and/or operation flowcharts disclosed in thisdocument and provide the generated signals to the one or moretransceivers 106 and 206. The one or more processors 102 and 202 mayreceive the signals (e.g., baseband signals) from the one or moretransceivers 106 and 206 and obtain the PDUs, SDUs, messages, controlinformation, data, or information according to the descriptions,functions, procedures, proposals, methods, and/or operation flowchartsdisclosed in this document.

The one or more processors 102 and 202 may be referred to ascontrollers, microcontrollers, microprocessors, or microcomputers. Theone or more processors 102 and 202 may be implemented by hardware,firmware, software, or a combination thereof. For example, one or moreapplication specific integrated circuits (ASICs), one or more digitalsignal processors (DSPs), one or more digital signal processing devices(DSPDs), one or more programmable logic devices (PLDs), or one or morefield programmable gate arrays (FPGAs) may be included in the one ormore processors 102 and 202. The descriptions, functions, procedures,proposals, methods, and/or operation flowcharts disclosed in thisdocument may be implemented using firmware or software, and the firmwareor software may be configured to include the modules, procedures, orfunctions. Firmware or software configured to perform the descriptions,functions, procedures, proposals, methods, and/or operation flowchartsdisclosed in this document may be included in the one or more processors102 and 202 or may be stored in the one or more memories 104 and 204 andexecuted by the one or more processors 102 and 202. The descriptions,functions, procedures, proposals, methods, and/or operation flowchartsdisclosed in this document may be implemented using firmware or softwarein the form of code, an instruction, and/or a set of instructions.

The one or more memories 104 and 204 may be connected to the one or moreprocessors 102 and 202 and store various types of data, signals,messages, information, programs, code, instructions, and/or commands.The one or more memories 104 and 204 may be configured to includeread-only memories (ROMs), random access memories (RAMs), electricallyerasable programmable read-only memories (EPROMs), flash memories, harddrives, registers, cash memories, computer-readable storage media,and/or combinations thereof. The one or more memories 104 and 204 may belocated at the interior and/or exterior of the one or more processors102 and 202. The one or more memories 104 and 204 may be connected tothe one or more processors 102 and 202 through various technologies suchas wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, controlinformation, and/or wireless signals/channels, mentioned in the methodsand/or operation flowcharts of this document, to one or more otherdevices. The one or more transceivers 106 and 206 may receive user data,control information, and/or wireless signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperation flowcharts disclosed in this document, from one or more otherdevices. For example, the one or more transceivers 106 and 206 may beconnected to the one or more processors 102 and 202 and transmit andreceive wireless signals. For example, the one or more processors 102and 202 may perform control so that the one or more transceivers 106 and206 may transmit user data, control information, or wireless signals toone or more other devices. The one or more processors 102 and 202 mayperform control so that the one or more transceivers 106 and 206 mayreceive user data, control information, or wireless signals from one ormore other devices. The one or more transceivers 106 and 206 may beconnected to the one or more antennas 108 and 208 and the one or moretransceivers 106 and 206 may be configured to transmit and receive userdata, control information, and/or wireless signals/channels, mentionedin the descriptions, functions, procedures, proposals, methods, and/oroperation flowcharts disclosed in this document, through the one or moreantennas 108 and 208. In this document, the one or more antennas may bea plurality of physical antennas or a plurality of logical antennas(e.g., antenna ports). The one or more transceivers 106 and 206 mayconvert received wireless signals/channels from RF band signals intobaseband signals in order to process received user data, controlinformation, and wireless signals/channels using the one or moreprocessors 102 and 202. The one or more transceivers 106 and 206 mayconvert the user data, control information, and wirelesssignals/channels processed using the one or more processors 102 and 202from the baseband signals into the RF band signals. To this end, the oneor more transceivers 106 and 206 may include (analog) oscillators and/orfilters.

5. Example of Use of Wireless Device to which the Present Disclosure isApplied

FIG. 36 illustrates another example of a wireless device applied to thepresent disclosure. The wireless device may be implemented in variousforms according to a use case/service (refer to FIG. 34).

Referring to FIG. 36, wireless devices 100 and 200 may correspond to thewireless devices 100 and 200 of FIG. 34 and may be configured to includevarious elements, components, units/portions, and/or modules. Forexample, each of the wireless devices 100 and 200 may include acommunication unit 110, a control unit 120, a memory unit 130, andadditional components 140. The communication unit 110 may include acommunication circuit 112 and transceiver(s) 114. For example, thecommunication circuit 112 may include the one or more processors 102 and202 and/or the one or more memories 104 and 204 of FIG. 36. For example,the transceiver(s) 114 may include the one or more transceivers 106 and206 and/or the one or more antennas 108 and 208 of FIG. 36. The controlunit 120 is electrically connected to the communication unit 110, thememory 130, and the additional components 140 and provides overallcontrol to the wireless device. For example, the control unit 120 maycontrol an electric/mechanical operation of the wireless device based onprograms/code/instructions/information stored in the memory unit 130.The control unit 120 may transmit the information stored in the memoryunit 130 to the outside (e.g., other communication devices) via thecommunication unit 110 through a wireless/wired interface or store, inthe memory unit 130, information received through the wireless/wiredinterface from the outside (e.g., other communication devices) via thecommunication unit 110.

The additional components 140 may be configured in various mannersaccording to type of the wireless device. For example, the additionalcomponents 140 may include at least one of a power unit/battery,input/output (I/O) unit, a driving unit, and a computing unit. Thewireless device may be implemented in the form of, not limited to, therobot (100 a of FIG. 34), the vehicles (100 b-1 and 100 b-2 of FIG. 34),the XR device (100 c of FIG. 34), the hand-held device (100 d of FIG.34), the home appliance (100 e of FIG. 34), the IoT device (100 f ofFIG. 34), a digital broadcasting terminal, a hologram device, a publicsafety device, an MTC device, a medical device, a FinTech device (or afinance device), a security device, a climate/environment device, the AIserver/device (400 of FIG. 34), the BSs (200 of FIG. 34), a networknode, or the like. The wireless device may be mobile or fixed accordingto a use case/service.

In FIG. 36, all of the various elements, components, units/portions,and/or modules in the wireless devices 100 and 200 may be connected toeach other through a wired interface or at least a part thereof may bewirelessly connected through the communication unit 110. For example, ineach of the wireless devices 100 and 200, the control unit 120 and thecommunication unit 110 may be connected by wire and the control unit 120and first units (e.g., 130 and 140) may be wirelessly connected throughthe communication unit 110. Each element, component, unit/portion,and/or module in the wireless devices 100 and 200 may further includeone or more elements. For example, the control unit 120 may beconfigured with a set of one or more processors. For example, thecontrol unit 120 may be configured with a set of a communication controlprocessor, an application processor, an electronic control unit (ECU), agraphical processing unit, and a memory control processor. In anotherexample, the memory 130 may be configured with a RAM, a dynamic RAM(DRAM), a ROM, a flash memory, a volatile memory, a non-volatile memory,and/or a combination thereof.

Hereinafter, an implementation example of FIG. 36 will be described indetail with reference to the drawings.

5.1. Example of Portable Device to which the Present Disclosure isApplied

FIG. 37 illustrates an exemplary portable device to which the presentdisclosure is applied. The portable device may be any of a smartphone, asmart pad, a wearable device (e.g., a smart watch or smart glasses), anda portable computer (e.g., a laptop). A portable device may also bereferred to as mobile station (MS), user terminal (UT), mobilesubscriber station (MSS), subscriber station (SS), advanced mobilestation (AMS), or wireless terminal (WT).

Referring to FIG. 37, a portable device 100 may include an antenna unit108, a communication unit 110, a control unit 120, a memory unit 130, apower supply unit 140 a, an interface unit 140 b, and an input/output(I/O) unit 140 c. The antenna unit 108 may be configured as a part ofthe communication unit 110. Blocks 110 to 130/140 a to 140 c correspondto the blocks 110 to 130/140 of FIG. 36, respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from other wireless devices or BSs. Thecontrol unit 120 may perform various operations by controllingcomponents of the portable device 100. The control unit 120 may includean application processor (AP). The memory unit 130 may storedata/parameters/programs/code/instructions needed to drive the portabledevice 100. Further, the memory unit 130 may store input/outputdata/information. The power supply unit 140 a may supply power to theportable device 100 and include a wired/wireless charging circuit, abattery, and so on. The interface unit 140 b may support connection ofthe portable device 100 to other external devices. The interface unit140 b may include various ports (e.g., an audio I/O port and a video I/Oport) for connection to external devices. The I/O unit 140 c may inputor output video information/signals, audio information/signals, data,and/or information input by a user. The I/O unit 140 c may include acamera, a microphone, a user input unit, a display unit 140 d, aspeaker, and/or a haptic module.

For example, in data communication, the I/O unit 140 c may obtaininformation/signals (e.g., touch, text, voice, images, or video) inputby the user, and the stored information/signals may be stored in thememory unit 130. The communication unit 110 may convert theinformation/signals stored in the memory into radio signals and transmitthe radio signals to other wireless devices directly or to a BS. Thecommunication unit 110 may receive radio signals from other wirelessdevices or the BS and then restore the received radio signals intooriginal information/signals. The restored information/signals may bestored in the memory unit 130 and may be output as various types (e.g.,text, voice, images, video, or haptic) through the I/O unit 140 c.

5.2. Example of Vehicle or Autonomous Driving Vehicle to which thePresent Disclosure is Applied

FIG. 38 illustrates a vehicle or an autonomous driving vehicle appliedto the present disclosure. The vehicle or autonomous driving vehicle maybe implemented as a mobile robot, a car, a train, a manned/unmannedaerial vehicle (AV), a ship, or the like.

Referring to FIG. 38, a vehicle or autonomous driving vehicle 100 mayinclude an antenna unit 108, a communication unit 110, a control unit120, a driving unit 140 a, a power supply unit 140 b, a sensor unit 140c, and an autonomous driving unit 140 d. The antenna unit 108 may beconfigured as a part of the communication unit 110. The blocks110/130/140 a to 140 d correspond to the blocks 110/130/140 of FIG. 36,respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from external devices such as othervehicles, BSs (e.g., gNBs and road side units), and servers. The controlunit 120 may perform various operations by controlling elements of thevehicle or the autonomous driving vehicle 100. The control unit 120 mayinclude an ECU. The driving unit 140 a may enable the vehicle or theautonomous driving vehicle 100 to drive on a road. The driving unit 140a may include an engine, a motor, a powertrain, a wheel, a brake, asteering device, and so on. The power supply unit 140 b may supply powerto the vehicle or the autonomous driving vehicle 100 and include awired/wireless charging circuit, a battery, and so on. The sensor unit140 c may obtain information about a vehicle state, ambient environmentinformation, user information, and so on. The sensor unit 140 c mayinclude an inertial measurement unit (IMU) sensor, a collision sensor, awheel sensor, a speed sensor, a slope sensor, a weight sensor, a headingsensor, a position module, a vehicle forward/backward sensor, a batterysensor, a fuel sensor, a tire sensor, a steering sensor, a temperaturesensor, a humidity sensor, an ultrasonic sensor, an illumination sensor,a pedal position sensor, and so on. The autonomous driving unit 140 dmay implement technology for maintaining a lane on which the vehicle isdriving, technology for automatically adjusting speed, such as adaptivecruise control, technology for autonomously driving along a determinedpath, technology for driving by automatically setting a route if adestination is set, and the like.

For example, the communication unit 110 may receive map data, trafficinformation data, and so on from an external server. The autonomousdriving unit 140 d may generate an autonomous driving route and adriving plan from the obtained data. The control unit 120 may controlthe driving unit 140 a such that the vehicle or autonomous drivingvehicle 100 may move along the autonomous driving route according to thedriving plan (e.g., speed/direction control). During autonomous driving,the communication unit 110 may aperiodically/periodically obtain recenttraffic information data from the external server and obtain surroundingtraffic information data from neighboring vehicles. During autonomousdriving, the sensor unit 140 c may obtain information about a vehiclestate and/or surrounding environment information. The autonomous drivingunit 140 d may update the autonomous driving route and the driving planbased on the newly obtained data/information. The communication unit 110may transfer information about a vehicle position, the autonomousdriving route, and/or the driving plan to the external server. Theexternal server may predict traffic information data using AI technologybased on the information collected from vehicles or autonomous drivingvehicles and provide the predicted traffic information data to thevehicles or the autonomous driving vehicles.

Those skilled in the art will appreciate that the various embodiments ofthe present disclosure may be carried out in other specific ways thanthose set forth herein without departing from the spirit and essentialcharacteristics of the various embodiments of the present disclosure.The above embodiments are therefore to be construed in all aspects asillustrative and not restrictive. The scope of the disclosure should bedetermined by the appended claims and their legal equivalents, not bythe above description, and all changes coming within the meaning andequivalency range of the appended claims are intended to be embracedtherein. It is obvious to those skilled in the art that claims that arenot explicitly cited in each other in the appended claims may bepresented in combination as an embodiment of the present disclosure orincluded as a new claim by a subsequent amendment after the applicationis filed.

Embodiments of the present disclosure are applicable to various wirelessaccess systems. The various wireless access systems include, forexample, a 3rd generation partnership project (3GPP) or 3GPP2 system.The embodiments of the present disclosure are applicable to alltechnical fields in which the various wireless access systems find theirapplications as well as the various wireless access systems.Furthermore, the proposed methods may also be applied to an mmWavecommunication system using an ultra high frequency band.

Additionally, the embodiments of the present disclosure are applicableto various applications including an autonomous driving vehicle, adrone, and so on.

What is claimed is:
 1. A method of operating by a user equipment (UE) ina wireless communication system, the method comprising: receivingconfiguration of a physical downlink shared channel (PDSCH) repetitionmode via a higher layer signaling; receiving a single downlink controlinformation (DCI) including information about two transmissionconfiguration indicator (TCI) states and information about a bandwidthpart (BWP); receiving two physical downlink shared channels (PDSCHs)based on the configuration information and the DCI, wherein a firstPDSCH of the two PDSCHs corresponds to a first TCI state of the two TCIstates and a second PDSCH of the two PDSCHs corresponds to a second TCIstate of the two TCI states, wherein, based on information about aphysical resource block (PRB) bundling size, the BWP is partitionedbased on the PRB bundling size, wherein, based on the PRB bundling sizebeing configured as a wideband: the first PDSCH is received in a half ofconsecutive PRBs within the BWP and the second PDSCH is received inremaining PRBs excluding the half of the consecutive PRBs within theBWP, and wherein, based on the PRB bundling size being configured as a 2PRBs or 4 PRBs: the first PDSCH and the second PDSCH are alternatelyreceived in units of 2 PRBs or 4 PRBs within the BWP.
 2. The method ofclaim 1, wherein resources in which the first PDSCH is receivedcorresponds to the first TCI state and resources in which the secondPDSCH is received corresponds to the second TCI state.
 3. The method ofclaim 2, wherein a first phase tracking-reference signal (PT-RS) for thefirst PDSCH is mapped based on the resources in which the first PDSCH isreceived and a second PT-RS for the second PDSCH are mapped based on theresources in which the second PDSCH is received.
 4. The method of claim1, wherein, the two PDSCHs are received from different transmission andreception points (TRPs).
 5. The method of claim 1, wherein the PRBbundling size is a unit to which a same precoding is applied.
 6. A userequipment (UE) operating in a wireless communication system, the UEcomprising: at least one transmitter; at least one receiver; at leastone processor; and at least one memory operably connected to the atleast one processor and configured to store instructions for causing theat least one processor to perform a specific operation when executed,wherein the specific operation comprises: receiving a single downlinkcontrol information (DCI) including information about two transmissionconfiguration indicator (TCI) states and information about a bandwidthpart (BWP); receiving two physical downlink shared channels (PDSCHs)based on the configuration information and the DCI, wherein a firstPDSCH of the two PDSCHs corresponds to a first TCI state of the two TCIstates and a second PDSCH of the two PDSCHs corresponds to a second TCIstate of the two TCI states, wherein, based on information about aphysical resource block (PRB) bundling size, the BWP is partitioned withthe PRB bundling size, wherein, based on the PRB bundling size beingconfigured as a wideband: the first PDSCH is received in a half ofconsecutive PRBs within the BWP and the second PDSCH is received inremaining PRBs excluding the half of the consecutive PRBs within theBWP, and wherein, based on the PRB bundling size being configured as a 2PRBs or 4 PRBs: the first PDSCH and the second PDSCH are alternatelyreceived in units of 2 PRBs or 4 PRBs within the BWP.
 7. The UE of claim6, wherein resources in which the first PDSCH is received corresponds tothe first TCI state and resources in which the second PDSCH is receivedcorresponds to the second TCI state.
 8. The UE of claim 7, wherein afirst phase tracking-reference signal (PT-RS) for the first PDSCH ismapped based on the resources in which the first PDSCH is received and asecond PT-RS for the second PDSCH are mapped based on the resources inwhich the second PDSCH is received.
 9. The UE of claim 6, wherein, thetwo PDSCHs are received from different transmission and reception points(TRPs).
 10. The UE of claim 6, wherein the UE communicates with at leastone of a mobile UE, a network, or an autonomous vehicle other than avehicle containing the UE.
 11. The UE of claim 6, wherein the PRBbundling size is a unit to which a same precoding is applied.
 12. Amethod of operating by a base station (BS) in a wireless communicationsystem, the method comprising: transmitting configuration of a physicaldownlink shared channel (PDSCH) repetition mode via a higher layersignaling; transmitting a single downlink control information (DCI)including information about two transmission configuration indicator(TCI) states and information about a bandwidth part (BWP); transmittingtwo physical downlink shared channels (PDSCHs) based on theconfiguration information and the DCI, wherein a first PDSCH of the twoPDSCHs corresponds to a first TCI state of the two TCI states and asecond PDSCH of the two PDSCHs corresponds to a second TCI state of thetwo TCI states, wherein, based on information about a physical resourceblock (PRB) bundling size, the BWP is partitioned with the PRB bundlingsize, wherein, based on the PRB bundling size being configured as awideband: the first PDSCH is transmitted in a half of consecutive PRBswithin the BWP and the second PDSCH is transmitted in remaining PRBsexcluding the half of the consecutive PRBs within the BWP, and wherein,based on the PRB bundling size being configured as a 2 PRBs or 4 PRBs:the first PDSCH and the second PDSCH are alternately transmitted inunits of 2 PRBs or 4 PRBs within the BWP.
 13. The method of claim 12,wherein resources in which the first PDSCH is transmitted corresponds tothe first TCI state and resources in which the second PDSCH istransmitted corresponds to the second TCI state.
 14. The method of claim13, wherein a first phase tracking-reference signal (PT-RS) for thefirst PDSCH is mapped based on the resources in which the first PDSCH istransmitted and a second PT-RS for the second PDSCH are mapped based onthe resources in which the second PDSCH is transmitted.
 15. The methodof claim 12, wherein, the two PDSCHs are transmitted from differenttransmission and reception points (TRPs).
 16. The method of claim 12,wherein the PRB bundling size is a unit to which a same precoding isapplied.
 17. A base station (BS) operation in a wireless communicationsystem, the BS comprising: at least one transmitter; at least onereceiver; at least one processor; and at least one memory operablyconnected to the at least one processor and configured to storeinstructions for causing the at least one processor to perform aspecific operation when executed, wherein the specific operationcomprises: transmitting configuration of a physical downlink sharedchannel (PDSCH) repetition mode via a higher layer signaling;transmitting a single downlink control information (DCI) includinginformation about two transmission configuration indicator (TCI) statesand information about a bandwidth part (BWP); transmitting two physicaldownlink shared channels (PDSCHs) based on the configuration informationand the DCI, wherein a first PDSCH of the two PDSCHs corresponds to afirst TCI state of the two TCI states and a second PDSCH of the twoPDSCHs corresponds to a second TCI state of the two TCI states, wherein,based on information about a physical resource block (PRB) bundlingsize, the BWP is partitioned with the PRB bundling size, wherein, basedon the PRB bundling size being configured as a wideband: the first PDSCHis transmitted in a half of consecutive PRBs within the BWP and thesecond PDSCH is transmitted in remaining PRBs excluding the half of theconsecutive PRBs within the BWP, and wherein, based on the PRB bundlingsize being configured as a 2 PRBs or 4 PRBs: the first PDSCH and thesecond PDSCH are alternately transmitted in units of 2 PRBs or 4 PRBswithin the BWP.